Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 11/16/13


AREA FORECAST DISCUSSION
NWS TAUNTON MA
1025 AM EST THU NOV 14 2013 .SYNOPSIS... HIGH PRESSURE WILL BUILD ACROSS THE MID ATLANTIC STATES TODAY THEN PUSH SOUTH OF NEW ENGLAND INTO THE WEEKEND. THIS WILL ALLOW MILDER TEMPERATURES TO MOVE INTO THE REGION. SOME MUCH NEEDED RAIN IS EXPECTED LATE MONDAY INTO TUESDAY. A RETURN TO MUCH COLDER WEATHER IS EXPECTED BY THE MIDDLE OF NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 1030 AM UPDATE...TEMPERATURES HAVE CLIMBED INTO THE LOW TO MID 40S ALREADY ACROSS MUCH OF THE AREA WITH A FEW UPPER 30S IN THE HIGHER ELEVATIONS UNDER SUNNY SKIES. OVERALL...THE FORECAST IS ON TRACK AND FEW EDITS WERE MADE. 7 AM UPDATE... EVALUATING H925 TEMPERATURES EXPECTED TO BE AROUND +4-6C...AND ASSUMING THE BOUNDARY LAYER WILL MIX-UP TO THIS PRESSURE LEVEL RESULTING IN A DRY-ADIABATIC PROFILE THROUGHOUT...THEN IT IS CERTAINLY PLAUSIBLE WITH THE ABUNDANT SUNSHINE /PRESENT CLOUDS SHOULD GRADUALLY CLEAR OUT OVER THE NEXT COUPLE OF HOURS/ THAT HIGH TEMPERATURES FOR INTERIOR NEW ENGLAND WILL GET INTO THE LOW- 50S. UTILIZING NEAR-TERM GUIDANCE SUCH AS THE HRRR FORECASTED HIGHS AROUND THE MID-50S FOR THIS AFTERNOON. CERTAINLY PLAUSIBLE... BUT FOR NOW TONED IT DOWN BASED ON THE PRIOR FORECAST. OTHERWISE THE REST OF THE FORECAST REMAINS ON TRACK OUTLINING THE ANTICIPATED WINDS AND HIGH PRESSURE. H850 JET ON ORDER OF 35-40 KNOTS WILL MOVE OFF THE SOUTHERN NEW ENGLAND THIS MORNING... PUSHING OFFSHORE DURING THE AFTERNOON. WILL SEE WIND GUSTS INCREASE TO 25-30 MPH WITH SOME GUSTS TO AROUND 35 MPH ALONG THE SOUTH COAST...CAPE COD AND THE ISLANDS. FORECASTED HIGHS ARE FOR THE LOW-50S ACROSS THE LOWER INTERIOR... WITH UPPER-40S ALONG THE COAST AND HIGHER TERRAIN. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/... TONIGHT... W-SW WINDS CONTINUE...BUT WILL DIMINISH BY AROUND MIDNIGHT. WARM AIR ADVECTION WILL ALSO CONTINUE TO WORK IN...WITH H85 TEMPS AROUND +7C TO +8C THROUGH THE NIGHT. EXPECT MOSTLY CLEAR SKIES THROUGH MIDNIGHT...THEN SOME CLOUDS WILL WORK IN. OVERNIGHT LOWS MAY DROP AS LOW AS THE LOWER 20S INLAND WITH THE LIGHT/VRBL OR CALM WINDS...RANGING TO AROUND 40 ON THE OUTER CAPE AND NANTUCKET. DEWPTS WILL START TO INCREASE DURING THE NIGHT AS WELL. FRIDAY... AS THE HIGH MOVES OFFSHORE...W-SW WINDS WILL PICK UP AGAIN WITH SOME GUSTS UP TO 25 MPH ACROSS SE MA AND THE S COAST. EXPECT BAND OF HIGH CLOUDS TO MOVE OFFSHORE DURING THE DAY. IT WILL BE MILDER WITH HIGHS IN THE 50S...RUNNING AROUND 5 DEGREES ABOVE SEASONAL NORMALS. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... HEADLINES... * DRY WEATHER FOR THE EARLY PART OF THE WEEKEND * WIDESPREAD RAIN LATE SUNDAY POSSIBLY AS LATE AS TUESDAY * ANOTHER SHOT OF ARCTIC AIR BY MIDWEEK INTO THE FOLLOWING WEEKEND */OVERVIEW AND MODEL CONSENSUS... WHILE TRENDS ARE WELL-ESTABLISHED...SPECIFICS REMAIN UNCERTAIN. FEEL THIS IS A CONSEQUENCE OF TWO FACTORS: ONE, THAT PACIFIC ENERGY TO EVOLVE INTO A TROUGH ACROSS THE CONUS HAS NOT BEEN WELL SAMPLED, AND TWO, THAT SOLUTIONS ARE HAVING DIFFICULTY AS TO THE INTERACTION AND POSSIBLE PHASING OF DISTURBANCES OVER THE NORTH-CENTRAL ATLANTIC. THE VARIANCE AND VARIABILITY IS CLEARLY EVIDENT PER ENSEMBLE MEMBER SOLUTIONS WITHIN THE CLIMATE PREDICTION CENTER ANALYSIS OF FORECAST NAO/AO TELECONNECTIONS...THOUGH A TREND TOWARDS A NEAR-NEUTRAL STATE HAS REMAINED CONSISTENT OVER THE PAST WEEK. GIVEN THAT BROAD-SCALE TRENDS ARE WELL-ESTABLISHED...AND FOLLOWING GUIDANCE PROVIDED BY WPC/HPC...A BLEND OF DETERMINISTIC SOLUTIONS IS FAVORED. */DAY-TO-DAY DETAILS... */FRIDAY NIGHT INTO SATURDAY NIGHT... DRY AIR AND DEEP-LAYER SUBSIDENCE WILL KEEP THE FORECAST PERIOD QUIET. A WEAK DISTURBANCE ALOFT SATURDAY MORNING MAY RESULT IN CLOUDS SOUTH OF THE AREA IN A REGION OF BETTER MOISTURE AVAILABILITY AND BROAD-ASCENT. OTHERWISE...INCREASING CLOUDS INTO SATURDAY NIGHT WITH ISENTROPIC MOIST ASCENT ALONG THE WESTERN PERIPHERY OF THE DEPARTING RIDGE. ONSHORE FLOW WILL RESULT IN TEMPERATURES CLOSER TO SEASONAL NORMALS...HIGHS AROUND THE LOW-50S WITH LOWS AROUND THE MID 30S. */SUNDAY INTO TUESDAY... A PERIOD OF WIDESPREAD RAIN IS CERTAIN ALONG AND AHEAD OF A COLD FRONT. EXACT TIMING AND LONGEVITY REMAIN UNCERTAIN. NOTED EARLIER... PWATS OF 1.5 INCHES ARE ROUGHLY 2 TO 3 STANDARD DEVIATIONS ABOVE NORMAL FOR THIS TIME OF YEAR...AND WITH STRONG FRONTOGENETICAL FORCING AND DEEP-LAYER ASCENT...THERE IS THE THREAT OF HEAVY RAIN. STILL SOME QUESTION AS TO WHETHER THIS WILL BE LOCALIZED SHOULD AN AREA OF LOW PRESSURE DEVELOP ALONG THE FRONT AND ACROSS OUR AREA AS CONTINUALLY SUGGESTED BY THE ECMWF. WITH MINOR TO MODERATE DROUGHT ESTIMATED ACROSS THE REGION...AND THE PROGRESSIVE NATURE OF THE FRONT AS AGREED UPON BY ALL SOLUTIONS...THERE IS LOW CONFIDENCE ON FLOODING. ALSO THERE DOES NOT SEEM TO BE MUCH INSTABILITY...SO LOW CONFIDENCE ON THUNDER. STRENGTH OF THE SYSTEM...WHICH IS UNDER QUESTION...WILL ULTIMATELY DETERMINE THE MAGNITUDE OF WARM-MOIST ADVECTION NORTHWARD PER SOUTHERLY FLOW. STRONGEST OF WINDS WILL BE ALONG THE SOUTH-SHORELINE BUT DO NOT FEEL THEY WILL REACH WIND ADVISORY CRITERIA. GALES WILL BE POSSIBLE OVER THE WATERS. TIMING AND STRENGTH OF THE WINDS WILL ALSO ULTIMATELY DETERMINE SURFACE TEMPERATURE AND DEWPOINT OUTCOMES. */WEDNESDAY INTO THE FOLLOWING WEEKEND... COLD DOME OF CANADIAN HIGH PRESSURE RETURNS. BELOW-NORMAL CONDITIONS PREVAILING INTO ROUGHLY THE END OF THE WEEK WITH THE HIGH SITUATED NORTH AND WEST OF THE REGION...RETURNING TO SEASONABLE LEVELS BY THE FOLLOWING WEEKEND WITH THE HIGH SHIFTING EAST RESULTING IN RETURN SOUTHERLY FLOW. && .AVIATION /15Z THURSDAY THROUGH MONDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH FRIDAY/...HIGH CONFIDENCE. VFR. INCREASING WEST-SOUTHWESTERLY FLOW WITH GUSTS AROUND 20 TO 25 KTS LATE MORNING INTO AFTERNOON...STRONGER ALONG THE SOUTH COASTLINE WITH GUSTS OF AROUND 30 KTS POSSIBLE. WINDS RELAX TONIGHT AS VFR CONTINUES TO PREVAIL...BUT RETURN TOMORROW ALONG THE SOUTH AND SOUTHEAST TERMINALS WITH GUSTS OF AROUND 20 KTS LATE MORNING INTO AFTERNOON. KBOS TAF...HIGH CONFIDENCE IN VFR. KBDL TAF...HIGH CONFIDENCE IN VFR. OUTLOOK...FRIDAY NIGHT THROUGH MONDAY NIGHT... */FRIDAY NIGHT INTO SATURDAY NIGHT...HIGH CONFIDENCE. VFR. LIGHT AND VARIABLE WINDS BECOMING EASTERLY LATE. INCREASING MID TO HIGH LEVEL CLOUDS. */SUNDAY INTO MONDAY NIGHT...MODERATE CONFIDENCE. LOW-END VFR TO MVFR CIGS. WIDESPREAD -RA WITH POSSIBLE +RA RESULTING IN IFR VSBYS. EAST-SOUTHEASTERLY WINDS INITIALLY INCREASING OUT OF THE SOUTH THE STRONGEST OF WHICH WILL BE ALONG THE SOUTH-SHORELINE WITH GUSTS OF AROUND 30 KTS. COLD FRONT SWEEPS THROUGH THE TERMINALS LATE BEHIND WHICH WINDS BACK WEST-NORTHWESTERLY REMAINING BLUSTERY. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH THURSDAY NIGHT/... TODAY...MODERATE TO HIGH CONFIDENCE. W-SW WINDS WILL INCREASE AS LOW LEVEL JET MOVES ACROSS THE SOUTHERN WATERS THROUGH MIDDAY. SMALL CRAFTS ARE UP FOR ALL WATERS EXCEPT THE SOUTHERN OUTER WATERS TO E OF CAPE COD WHERE GUSTS WILL REACH 35 KT. HAVE PUT GALES UP THERE. AS THE JET MOVES OFFSHORE THIS AFTERNOON...WINDS WILL BEGIN TO SLOWLY DIMINISH. SEAS BUILD UP TO 6-8 FT ON THE SOUTHERN WATERS. TONIGHT...MODERATE TO HIGH CONFIDENCE. EXPECT W-SW WINDS TO DIMINISH TONIGHT. WILL SEE GUSTS UP TO 25 KT ON THE OUTER WATERS EARLY. SMALL CRAFTS ON THE NEAR SHORE WATERS SHOULD COME DOWN EARLY...BUT WILL REMAIN UP ON THE OUTER WATERS THROUGH THE NIGHT MAINLY FOR SEAS UP TO 6 FT. FRIDAY...HIGH CONFIDENCE. EXPECT W WINDS TO CONTINUE TO GUST UP TO 20 KT AND SEAS AOA 5 FT ON THE SOUTHERN OUTER WATERS...THOUGH SHOULD DIMINISH DURING THE DAY. OTHERWISE...WINDS AND SEAS BELOW SMALL CRAFT CRITERIA. OUTLOOK...FRIDAY NIGHT THROUGH MONDAY NIGHT... */FRIDAY NIGHT INTO SATURDAY NIGHT...HIGH CONFIDENCE. LIGHT AND VARIABLE WINDS BECOMING EASTERLY LATE. SEAS SHOULD REMAIN BELOW 5 FEET OVER ALL WATERS. */SUNDAY INTO MONDAY NIGHT...MODERATE CONFIDENCE. WIDESPREAD RAIN WITH EMBEDDED HEAVIER SHOWERS. EAST-SOUTHEASTERLY WINDS INITIALLY INCREASING OUT OF THE SOUTH THE STRONGEST OF WHICH WILL BE ALONG THE SOUTH WATERS WITH GUSTS OF AROUND 30 KTS POSSIBLY EXCEEDING GALE FORCE. ANTICIPATE SEAS TO BE ABOVE 5 FEET FOR A TIME OVER ALL WATERS EXCEPT INNER BAYS AND HARBORS. COLD FRONT SWEEPS THROUGH THE WATERS LATE BEHIND WHICH WINDS BACK WEST-NORTHWESTERLY REMAINING BLUSTERY. GALES MAY CONTINUE FOR ALL WATERS. SEAS TO REMAIN CHOPPY. && .FIRE WEATHER... HIGH PRESSURE ACROSS THE MID ATLANTIC WILL MOVE OFF THE COAST WITH RETURN W-SW FLOW IN PLACE INTO THIS WEEKEND. VERY LOW DEWPTS REMAIN IN PLACE...IN THE TEENS EARLY THIS MORNING...WILL RISE ONLY SLIGHTLY AWAY FROM THE S COAST...CAPE COD AND THE ISLANDS DURING THE DAY. WILL ALSO SEE W-SW WINDS PICK UP TO 20-25 MPH WITH SOME GUSTS TO 30 MPH ACROSS INLAND AREAS. TODAY...MINIMUM RELATIVE HUMIDITIES THIS AFTERNOON WILL DROP TO BETWEEN 30 AND 35 PERCENT ACROSS AREAS AWAY FROM THE IMMEDIATE COAST. WITH THE LACK OF RAINFALL OVER THE LAST FEW WEEKS ALONG WITH THE INCREASING WIND ESPECIALLY ACROSS E AND CENTRAL MA/N CT INTO N RI AND THE LOW RELATIVE HUMIDITY VALUES...THERE MAY BE CAUSE FOR SOME CONCERN FOR FIRE WEATHER INTERESTS. FRIDAY...MINIMUM RELATIVE HUMIDITIES WILL DROP TO BETWEEN 25 AND 35 PERCENT AGAIN AROUND MIDDAY OR EARLY AFTERNOON ACROSS AREAS AWAY FROM THE S COAST. HOWEVER...W-SW WINDS WILL BE LOWER... THOUGH MAY GUST UP TO 20 MPH ACROSS N RI AND INTERIOR SE MA. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR ANZ232- 251. SMALL CRAFT ADVISORY UNTIL 1 AM EST FRIDAY FOR ANZ233-234-250. SMALL CRAFT ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR ANZ230. SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR ANZ231. SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ236. SMALL CRAFT ADVISORY UNTIL 7 AM EST FRIDAY FOR ANZ235-237. GALE WARNING UNTIL 6 PM EST THIS EVENING FOR ANZ254>256. && $$ SYNOPSIS...SIPPRELL/EVT NEAR TERM...RLG/SIPPRELL/EVT SHORT TERM...EVT LONG TERM...SIPPRELL AVIATION...SIPPRELL/EVT MARINE...SIPPRELL/EVT FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS TAUNTON MA
642 AM EST THU NOV 14 2013 .SYNOPSIS... HIGH PRESSURE WILL BUILD ACROSS THE MID ATLANTIC STATES TODAY THEN PUSH SOUTH OF NEW ENGLAND INTO THE WEEKEND. THIS WILL ALLOW MILDER TEMPERATURES TO MOVE INTO THE REGION. SOME MUCH NEEDED RAIN IS EXPECTED LATE MONDAY INTO TUESDAY. A RETURN TO MUCH COLDER WEATHER IS EXPECTED BY THE MIDDLE OF NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 7 AM UPDATE... CONDITIONS ARE ACTUALLY WARMING BY A FEW DEGREES EARLY THIS MORNING WITH THE ONSHORE SOUTHWESTERLY FLOW. AS OF 4 AM... TEMPERATURES ACROSS SOUTHEAST NEW ENGLAND HAD WARMED BY A FEW DEGREES...PRIOR TO SUNRISE. EVALUATING H925 TEMPERATURES EXPECTED TO BE AROUND +4-6C...AND ASSUMING THE BOUNDARY LAYER WILL MIX-UP TO THIS PRESSURE LEVEL RESULTING IN A DRY-ADIABATIC PROFILE THROUGHOUT...THEN IT IS CERTAINLY PLAUSIBLE WITH THE ABUNDANT SUNSHINE /PRESENT CLOUDS SHOULD GRADUALLY CLEAR OUT OVER THE NEXT COUPLE OF HOURS/ THAT HIGH TEMPERATURES FOR INTERIOR NEW ENGLAND WILL GET INTO THE LOW- 50S. UTILIZING NEAR- TERM GUIDANCE SUCH AS THE HRRR FORECASTED HIGHS AROUND THE MID-50S FOR THIS AFTERNOON. CERTAINLY PLAUSIBLE... BUT FOR NOW TONED IT DOWN BASED ON THE PRIOR FORECAST. OTHERWISE THE REST OF THE FORECAST REMAINS ON TRACK OUTLINING THE ANTICIPATED WINDS AND HIGH PRESSURE. H850 JET ON ORDER OF 35-40 KNOTS WILL MOVE OFF THE SOUTHERN NEW ENGLAND THIS MORNING... PUSHING OFFSHORE DURING THE AFTERNOON. WILL SEE WIND GUSTS INCREASE TO 25-30 MPH WITH SOME GUSTS TO AROUND 35 MPH ALONG THE SOUTH COAST...CAPE COD AND THE ISLANDS. FORECASTED HIGHS ARE FOR THE LOW-50S ACROSS THE LOWER INTERIOR... WITH UPPER-40S ALONG THE COAST AND HIGHER TERRAIN. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/... TONIGHT... W-SW WINDS CONTINUE...BUT WILL DIMINISH BY AROUND MIDNIGHT. WARM AIR ADVECTION WILL ALSO CONTINUE TO WORK IN...WITH H85 TEMPS AROUND +7C TO +8C THROUGH THE NIGHT. EXPECT MOSTLY CLEAR SKIES THROUGH MIDNIGHT...THEN SOME CLOUDS WILL WORK IN. OVERNIGHT LOWS MAY DROP AS LOW AS THE LOWER 20S INLAND WITH THE LIGHT/VRBL OR CALM WINDS...RANGING TO AROUND 40 ON THE OUTER CAPE AND NANTUCKET. DEWPTS WILL START TO INCREASE DURING THE NIGHT AS WELL. FRIDAY... AS THE HIGH MOVES OFFSHORE...W-SW WINDS WILL PICK UP AGAIN WITH SOME GUSTS UP TO 25 MPH ACROSS SE MA AND THE S COAST. EXPECT BAND OF HIGH CLOUDS TO MOVE OFFSHORE DURING THE DAY. IT WILL BE MILDER WITH HIGHS IN THE 50S...RUNNING AROUND 5 DEGREES ABOVE SEASONAL NORMALS. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... HEADLINES... * DRY WEATHER FOR THE EARLY PART OF THE WEEKEND * WIDESPREAD RAIN LATE SUNDAY POSSIBLY AS LATE AS TUESDAY * ANOTHER SHOT OF ARCTIC AIR BY MIDWEEK INTO THE FOLLOWING WEEKEND */OVERVIEW AND MODEL CONSENSUS... WHILE TRENDS ARE WELL-ESTABLISHED...SPECIFICS REMAIN UNCERTAIN. FEEL THIS IS A CONSEQUENCE OF TWO FACTORS: ONE, THAT PACIFIC ENERGY TO EVOLVE INTO A TROUGH ACROSS THE CONUS HAS NOT BEEN WELL SAMPLED, AND TWO, THAT SOLUTIONS ARE HAVING DIFFICULTY AS TO THE INTERACTION AND POSSIBLE PHASING OF DISTURBANCES OVER THE NORTH-CENTRAL ATLANTIC. THE VARIANCE AND VARIABILITY IS CLEARLY EVIDENT PER ENSEMBLE MEMBER SOLUTIONS WITHIN THE CLIMATE PREDICTION CENTER ANALYSIS OF FORECAST NAO/AO TELECONNECTIONS...THOUGH A TREND TOWARDS A NEAR-NEUTRAL STATE HAS REMAINED CONSISTENT OVER THE PAST WEEK. GIVEN THAT BROAD-SCALE TRENDS ARE WELL-ESTABLISHED...AND FOLLOWING GUIDANCE PROVIDED BY WPC/HPC...A BLEND OF DETERMINISTIC SOLUTIONS IS FAVORED. */DAY-TO-DAY DETAILS... */FRIDAY NIGHT INTO SATURDAY NIGHT... DRY AIR AND DEEP-LAYER SUBSIDENCE WILL KEEP THE FORECAST PERIOD QUIET. A WEAK DISTURBANCE ALOFT SATURDAY MORNING MAY RESULT IN CLOUDS SOUTH OF THE AREA IN A REGION OF BETTER MOISTURE AVAILABILITY AND BROAD-ASCENT. OTHERWISE...INCREASING CLOUDS INTO SATURDAY NIGHT WITH ISENTROPIC MOIST ASCENT ALONG THE WESTERN PERIPHERY OF THE DEPARTING RIDGE. ONSHORE FLOW WILL RESULT IN TEMPERATURES CLOSER TO SEASONAL NORMALS...HIGHS AROUND THE LOW-50S WITH LOWS AROUND THE MID 30S. */SUNDAY INTO TUESDAY... A PERIOD OF WIDESPREAD RAIN IS CERTAIN ALONG AND AHEAD OF A COLD FRONT. EXACT TIMING AND LONGEVITY REMAIN UNCERTAIN. NOTED EARLIER... PWATS OF 1.5 INCHES ARE ROUGHLY 2 TO 3 STANDARD DEVIATIONS ABOVE NORMAL FOR THIS TIME OF YEAR...AND WITH STRONG FRONTOGENETICAL FORCING AND DEEP-LAYER ASCENT...THERE IS THE THREAT OF HEAVY RAIN. STILL SOME QUESTION AS TO WHETHER THIS WILL BE LOCALIZED SHOULD AN AREA OF LOW PRESSURE DEVELOP ALONG THE FRONT AND ACROSS OUR AREA AS CONTINUALLY SUGGESTED BY THE ECMWF. WITH MINOR TO MODERATE DROUGHT ESTIMATED ACROSS THE REGION...AND THE PROGRESSIVE NATURE OF THE FRONT AS AGREED UPON BY ALL SOLUTIONS...THERE IS LOW CONFIDENCE ON FLOODING. ALSO THERE DOES NOT SEEM TO BE MUCH INSTABILITY...SO LOW CONFIDENCE ON THUNDER. STRENGTH OF THE SYSTEM...WHICH IS UNDER QUESTION...WILL ULTIMATELY DETERMINE THE MAGNITUDE OF WARM-MOIST ADVECTION NORTHWARD PER SOUTHERLY FLOW. STRONGEST OF WINDS WILL BE ALONG THE SOUTH-SHORELINE BUT DO NOT FEEL THEY WILL REACH WIND ADVISORY CRITERIA. GALES WILL BE POSSIBLE OVER THE WATERS. TIMING AND STRENGTH OF THE WINDS WILL ALSO ULTIMATELY DETERMINE SURFACE TEMPERATURE AND DEWPOINT OUTCOMES. */WEDNESDAY INTO THE FOLLOWING WEEKEND... COLD DOME OF CANADIAN HIGH PRESSURE RETURNS. BELOW-NORMAL CONDITIONS PREVAILING INTO ROUGHLY THE END OF THE WEEK WITH THE HIGH SITUATED NORTH AND WEST OF THE REGION...RETURNING TO SEASONABLE LEVELS BY THE FOLLOWING WEEKEND WITH THE HIGH SHIFTING EAST RESULTING IN RETURN SOUTHERLY FLOW. && .AVIATION /12Z THURSDAY THROUGH MONDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH FRIDAY/...HIGH CONFIDENCE. VFR. DISSIPATING MID- TO UPPER-LEVEL CIGS. INCREASING WEST- SOUTHWESTERLY FLOW WITH GUSTS AROUND 20 TO 25 KTS LATE MORNING INTO AFTERNOON...STRONGER ALONG THE SOUTH COASTLINE WITH GUSTS OF AROUND 30 KTS POSSIBLE. WINDS RELAX TONIGHT AS VFR CONTINUES TO PREVAIL...BUT RETURN TOMORROW ALONG THE SOUTH AND SOUTHEAST TERMINALS WITH GUSTS OF AROUND 20 KTS LATE MORNING INTO AFTERNOON. KBOS TAF...HIGH CONFIDENCE IN VFR. KBDL TAF...HIGH CONFIDENCE IN VFR. OUTLOOK...FRIDAY NIGHT THROUGH MONDAY NIGHT... */FRIDAY NIGHT INTO SATURDAY NIGHT...HIGH CONFIDENCE. VFR. LIGHT AND VARIABLE WINDS BECOMING EASTERLY LATE. INCREASING MID TO HIGH LEVEL CLOUDS. */SUNDAY INTO MONDAY NIGHT...MODERATE CONFIDENCE. LOW-END VFR TO MVFR CIGS. WIDESPREAD -RA WITH POSSIBLE +RA RESULTING IN IFR VSBYS. EAST-SOUTHEASTERLY WINDS INITIALLY INCREASING OUT OF THE SOUTH THE STRONGEST OF WHICH WILL BE ALONG THE SOUTH-SHORELINE WITH GUSTS OF AROUND 30 KTS. COLD FRONT SWEEPS THROUGH THE TERMINALS LATE BEHIND WHICH WINDS BACK WEST-NORTHWESTERLY REMAINING BLUSTERY. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH THURSDAY NIGHT/... TODAY...MODERATE TO HIGH CONFIDENCE. W-SW WINDS WILL INCREASE AS LOW LEVEL JET MOVES ACROSS THE SOUTHERN WATERS THROUGH MIDDAY. SMALL CRAFTS ARE UP FOR ALL WATERS EXCEPT THE SOUTHERN OUTER WATERS TO E OF CAPE COD WHERE GUSTS WILL REACH 35 KT. HAVE PUT GALES UP THERE. AS THE JET MOVES OFFSHORE THIS AFTERNOON...WINDS WILL BEGIN TO SLOWLY DIMINISH. SEAS BUILD UP TO 6-8 FT ON THE SOUTHERN WATERS. TONIGHT...MODERATE TO HIGH CONFIDENCE. EXPECT W-SW WINDS TO DIMINISH TONIGHT. WILL SEE GUSTS UP TO 25 KT ON THE OUTER WATERS EARLY. SMALL CRAFTS ON THE NEAR SHORE WATERS SHOULD COME DOWN EARLY...BUT WILL REMAIN UP ON THE OUTER WATERS THROUGH THE NIGHT MAINLY FOR SEAS UP TO 6 FT. FRIDAY...HIGH CONFIDENCE. EXPECT W WINDS TO CONTINUE TO GUST UP TO 20 KT AND SEAS AOA 5 FT ON THE SOUTHERN OUTER WATERS...THOUGH SHOULD DIMINISH DURING THE DAY. OTHERWISE...WINDS AND SEAS BELOW SMALL CRAFT CRITERIA. OUTLOOK...FRIDAY NIGHT THROUGH MONDAY NIGHT... */FRIDAY NIGHT INTO SATURDAY NIGHT...HIGH CONFIDENCE. LIGHT AND VARIABLE WINDS BECOMING EASTERLY LATE. SEAS SHOULD REMAIN BELOW 5 FEET OVER ALL WATERS. */SUNDAY INTO MONDAY NIGHT...MODERATE CONFIDENCE. WIDESPREAD RAIN WITH EMBEDDED HEAVIER SHOWERS. EAST-SOUTHEASTERLY WINDS INITIALLY INCREASING OUT OF THE SOUTH THE STRONGEST OF WHICH WILL BE ALONG THE SOUTH WATERS WITH GUSTS OF AROUND 30 KTS POSSIBLY EXCEEDING GALE FORCE. ANTICIPATE SEAS TO BE ABOVE 5 FEET FOR A TIME OVER ALL WATERS EXCEPT INNER BAYS AND HARBORS. COLD FRONT SWEEPS THROUGH THE WATERS LATE BEHIND WHICH WINDS BACK WEST-NORTHWESTERLY REMAINING BLUSTERY. GALES MAY CONTINUE FOR ALL WATERS. SEAS TO REMAIN CHOPPY. && .FIRE WEATHER... HIGH PRESSURE ACROSS THE MID ATLANTIC WILL MOVE OFF THE COAST WITH RETURN W-SW FLOW IN PLACE INTO THIS WEEKEND. VERY LOW DEWPTS REMAIN IN PLACE...IN THE TEENS EARLY THIS MORNING...WILL RISE ONLY SLIGHTLY AWAY FROM THE S COAST...CAPE COD AND THE ISLANDS DURING THE DAY. WILL ALSO SEE W-SW WINDS PICK UP TO 20-25 MPH WITH SOME GUSTS TO 30 MPH ACROSS INLAND AREAS. TODAY...MINIMUM RELATIVE HUMIDITIES THIS AFTERNOON WILL DROP TO BETWEEN 30 AND 35 PERCENT ACROSS AREAS AWAY FROM THE IMMEDIATE COAST. WITH THE LACK OF RAINFALL OVER THE LAST FEW WEEKS ALONG WITH THE INCREASING WIND ESPECIALLY ACROSS E AND CENTRAL MA/N CT INTO N RI AND THE LOW RELATIVE HUMIDITY VALUES...THERE MAY BE CAUSE FOR SOME CONCERN FOR FIRE WEATHER INTERESTS. FRIDAY...MINIMUM RELATIVE HUMIDITIES WILL DROP TO BETWEEN 25 AND 35 PERCENT AGAIN AROUND MIDDAY OR EARLY AFTERNOON ACROSS AREAS AWAY FROM THE S COAST. HOWEVER...W-SW WINDS WILL BE LOWER... THOUGH MAY GUST UP TO 20 MPH ACROSS N RI AND INTERIOR SE MA. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR ANZ232. SMALL CRAFT ADVISORY UNTIL 1 AM EST FRIDAY FOR ANZ233-234. SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO 5 PM EST THIS AFTERNOON FOR ANZ230. SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR ANZ231. SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ236. SMALL CRAFT ADVISORY UNTIL 7 AM EST FRIDAY FOR ANZ235-237. SMALL CRAFT ADVISORY UNTIL 1 AM EST FRIDAY FOR ANZ250. SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR ANZ251. GALE WARNING FROM 10 AM THIS MORNING TO 6 PM EST THIS EVENING FOR ANZ254>256. && $$ SYNOPSIS...SIPPRELL/EVT NEAR TERM...SIPPRELL/EVT SHORT TERM...EVT LONG TERM...SIPPRELL AVIATION...SIPPRELL/EVT MARINE...SIPPRELL/EVT FIRE WEATHER...EVT
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
942 PM EST FRI NOV 15 2013 .SYNOPSIS... HIGH PRESSURE WILL CONTINUE TO REMAIN OFFSHORE IN THE ATLANTIC OVERNIGHT. A COLD FRONT APPROACHES FROM THE WEST AND CROSSES THE AREA SUNDAY NIGHT INTO MONDAY MORNING. ANOTHER HIGH PRESSURE BUILDS FROM THE NORTH ON TUESDAY. HIGH PRESSURE WILL REMAIN TO THE NORTH INTO FRIDAY. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... A COMBINATION OF THE GFS AND CAN RGEM HAS VERIFIED THE BEST WITH THE ONGOING PCPN. OVERALL NO BIG CHANGES AS AN UPPER AIR IMPULSE WILL FIND A LESS HOSPITABLE ENVIRONMENT FOR PCPN TO MAKE IT TO THE GROUND, ESPECIALLY THE NORTHERN PART OF OUR CWA. THE BIGGEST ADJUSTMENT HAS BEEN TO TEMPERATURES AS A CIRRUS HOLE HAS DEVELOPED OVER OUR CWA AND HAS PERMITTED TEMPERATURES TO DROP LIKE A ROCK WITH LIGHT WINDS AND LOW DEW POINTS. WE HAVE PRACTICALLY RADIATED TO THE DEW POINT IN SOME PLACES, SO BETWEEN THE THICKER CIRRUS NOW AS CLOSE AS THE MD EASTERN SHORE ARRIVING AND PRETTY MUCH NO WHERE TO GO, PLENTY OF OUTLYING AREA MINS ARE GOING TO BE OCCURRING BEFORE MIDNIGHT BEFORE TEMPERATURE REBOUND WITH THE ARRIVAL OF THICKER CLOUDS. SURFACE HIGH PRESSURE TO OUR EAST WILL WEAKEN A BIT OVERNIGHT. AT THE SAME TIME, A WEAK OPEN WAVE AT THE MID LEVELS WILL MOVE ACROSS THE APPALACHIANS, BEFORE MOVING OFF THE NORTHERN MID-ATLANTIC COAST. IN RESPONSE TO 12Z DATA, POPS HAVE BEEN ADJUSTED ACROSS THE DELMARVA (INCREASED) AND ALSO HAVE BEEN ADDED A BIT FURTHER TO THE NORTH. WINDS WILL BE LIGHT OUT OF THE SOUTHWEST. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/... LATEST MODEL GUIDANCE SUGGESTING A SLOWER EXIT OF PCPN CHANCES IN SERN NJ AND DE ON SATURDAY MORNING. GIVEN THE HRRR AND WRF-NMMB NORMALLY HAVE A SLOW TIMING BIAS, ONLY A MODEST INCREASE IN POPS WAS DONE AT THE START OF THE MORNING. THE MID-LEVEL SHORT WAVE WILL CONTINUE TO PRESS TO THE EAST TOMORROW TAKING THE THREAT OF SHOWERS WITH IT. TIMING WISE...POPS START TO SHRINK EASTWARD TOWARD DAYBREAK AND ALL POPS HAVE BEEN REMOVED BY MIDDAY. TOTAL QPF AMOUNTS SHOULD RANGE FROM ABOUT A .10 ACROSS THE DELMARVA TO JUST A FEW HUNDREDTHS FURTHER NORTH. ONCE THE SHORT WAVE PULLS EAST, WE SHOULD SEE SOME DECREASE IN CLOUDS ESPECIALLY UP ACROSS THE NORTHERN ZONES. WINDS WILL SHIFT FROM THE SOUTHWEST AT DAYBREAK TO THE SOUTHEAST LATER IN THE DAY. TEMPERATURES WILL TOP OUT NEAR 50 ACROSS THE FAR NORTHWESTERN ZONES TO AROUND 60 ON THE COASTAL PLAIN. && .LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/... HIGH PRESSURE WILL BE OFFSHORE AT THE BEGINNING OF THE EXTENDED PERIOD. THE RETURN FLOW AROUND IT WILL BE USHERING IN MOISTURE AND MILDER TEMPERATURES FOR SATURDAY NIGHT THROUGH SUNDAY NIGHT. THIS MOISTURE ALONG WITH AN APPROACHING LOW/FRONT SUNDAY NIGHT WILL BRING HIGHER CHC FOR PCPN BEGINNING SUN NIGHT AND LASTING INTO MONDAY. A COLD FRONT WILL CROSS THE AREA MONDAY MORNING WITH DRIER AND COLDER AIR FLOWING IN BEHIND IT. POPS FOR THE SUN NIGHT/MONDAY PERIOD REACH THE CATEGORICAL RANGE...THEN DROP BACK TO THE CHC RANGE FOR A FEW HOURS FOLLOWING THE FRONT. TEMPERATURES FROM SAT NIGHT THROUGH SUN NIGHT WILL BE ABOVE NORMAL...PERHAPS AS MUCH AS 10 DEGREES ABOVE NORMAL SUN AND SUN NIGHT. OVERALL QPF FROM THE SYSTEM LOOKS TO BE AROUND 0.5 TO 1.0 INCHES. THE COLDER AIR WILL DEEPEN ACROSS THE REGION MON NIGHT AND PERSIST THROUGH THE MID-WEEK PERIOD. STRONG HIGH PRESSURE WILL MOVE ACROSS THE OHIO VALLEY AND GREAT LAKES MON/TUE...THEN SPRAWL ACROSS THE MIDDLE ATLANTIC AND NORTHEAST WED/THU. THIS HIGH WILL KEEP THE WEATHER DRY ACROSS THE AREA. TEMPERATURES WILL MODERATE BACK TO NEAR NORMAL FOR THE LAST TWO DAYS OF THE WORK WEEK. && .AVIATION /02Z SATURDAY THROUGH WEDNESDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. THE 00Z TAFS CONTINUED THE PRECIP CHANCES OVERNIGHT INTO SATURDAY MORNING WITH SOME MVFR CONDITIONS POSSIBLE. REST OF THIS EVENING...VFR MID OR MORE LIKELY CIRRUS DECK CIG. WINDS LIGHT AND VARIABLE. OVERNIGHT...VFR CIGS SHOULD LOWER TO A MID DECK AND THEN A LOWER VFR STRATOCU DECK LEVEL WITH LIGHT AND VARIABLE WINDS. PRECIPITATION IS LIKELY TO OVERSPREAD THE TERMINALS, BUT BE VERY LIGHT NORTH AND WEST OF THE KPHL METRO AIRPORTS. PCPN ASSOCIATED MVFR CIG RESTRICTIONS ARE AT KMIV AND KACY TOWARD MORNING, NOT CONFIDENT ABOUT INCLUDING IN THE KPHL AREAS AIRPORTS AND FARTHER TO THE NORTHWEST NOT EXPECTING IT TO OCCUR. SATURDAY MORNING...RAIN CHANCES ENDING AT SERN AIRPORTS ALONG WITH MVFR CIG CONCERNS. ELSEWHERE, THE VFR SC CIG SHOULD BE GONE (AND REPLACED WITH A CIRRUS CIG) AS THE MORNING PROGRESSES. A LIGHT SE WIND FORECAST. SATURDAY AFTERNOON...VFR WITH LIGHT SOUTHEAST WINDS. A SCATTERED STRATOCU/CU DECK IS FORECAST WITH THE MOST LIKELY CIG BEING AT CIRRUS LEVELS. AT KPHL WE INCLUDED A FORECAST GROUP SHOWING MVFR CONDITIONS DEVELOPING LATE SATURDAY EVENING. OUTLOOK... SAT NIGHT THRU MONDAY...MVFR/IFR CONDITIONS WITH LOW CLOUDS AND FREQUENT SHOWERS. GUSTY S/SW WINDS UNTIL MONDAY THEN WINDS SHIFT TO W/NW. MON EVENING THRU WED...MOSTLY VFR. && .MARINE... NO HEADLINES IN THE SHORT TERM.... TONIGHT...IN GENERAL, OUR WATERS WILL SEE THE SOUTHWEST WINDS SLACKEN A BIT AND BECOME MORE WESTERLY. SEAS WILL BE 2 TO 3 FEET ON THE OCEAN, LESS ON THE DELAWARE BAY. SATURDAY...WINDS WILL GO VARIABLE FOR A SHORT TIME AS THEY TRANSITION FROM THE SOUTHWEST TO THE SOUTHEAST. WINDS LOOK LIGHT IN THE 5 TO 10 KT RANGE. SEAS WILL RUN ABOUT 2 FEET ON THE OCEAN AND LESS ON DELAWARE BAY. OUTLOOK... SAT NIGHT THRU SUN AFTERNOON...INCREASING WINDS/SEAS BUT CONDITIONS SUB-SCA. SUN EVENING THRU TUESDAY...SCA CONDITIONS EXPECTED WITH A STORM SYSTEM AND COLD FRONT CROSSING THE WATERS MONDAY. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...NONE. && $$ SYNOPSIS...O`HARA/RODRIGUES NEAR TERM...GIGI/KRUZDLO SHORT TERM...KRUZDLO LONG TERM...O`HARA AVIATION...GIGI/O`HARA MARINE...KRUZDLO/O`HARA
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
822 PM EST Fri Nov 15 2013 .NEAR TERM [Through Rest of Tonight]... The large scale regional pattern is highlighted this evening by a broad H5 trough with its axis across TN Valley Swd to MS and into the Nrn Gulf of Mexico, with weak shortwaves over E/Cntrl AL and in the NE Gulf. At surface, an area of high pressure resides over the Wrn Atlc east of NC with its ridge axis Swwd into the NE Gulf of Mexico. The combination of the approaching trough/shortwaves with WLY steering flow aloft, weak isentropic lift, and light onshore flow brought a broad area of light rain or drizzle across CWFA Fri afternoon and evening, keeping extensive cloud cover and moisture in place. By sunrise Sat, the aforementioned trough axis will have reached Suwannee Valley with the Gulf shortwave exiting our waters. This will continue to push any remaining light rain in southeast parts of our region Ewd, with noticeably diminished forcing in the wake of the trough. Both the GFS and NAM show a very weak mid/upper ridge moving over our area between 02z-08z. HRRR and other HI RES models show light rain or drizzle continuing to push off to the southeast of our region by 03Z. However, with RAP13 soundings showing that area PWATs will remain between 1.2 and 1.5 inches through the night, and with the surface high to our NE, cool low level NE flow on top of residual moisture from today`s rain will help support the development of low clouds and patchy fog overnight. Chances of fog are greatest in our GA and AL counties. Overnight low temperatures will be mild, generally in the low to mid 50s inland, and near 60 in coastal regions. && .SHORT TERM [Saturday Through Sunday Night]... Except for some lingering moisture/lift in our North FL zones, most of our forecast area will be under the influence of 500 mb ridging Saturday. We have low PoPs (generally around 20%) for Saturday and Saturday night. The PoP will increase Sunday from northwest to southeast as a cold front approaches. The timing of the highest rain chances (around 70%) will be Sunday night and Monday, though the QPF/omega fields suggest that the frontal rain band will be weakening as it moves through. The prospects for severe storms appear low due to poor instability, marginal vertical wind shear, and weakening Q-G forcing. Temperatures will be above average, though abundant clouds will help prevent high temperatures from reaching 80 deg (except around Cross City Sunday afternoon). The lows Sunday morning will be unusually warm- in the mid 60s. && .LONG TERM [Monday through Friday]... The relatively zonal 500 mb flow over the Gulf Coast states will give way to ridging late in the work week. There was some discrepancy between the GFS and ECMWF Tuesday and Wednesday, as the GFS keeps a band of deep layer moisture and weak Q-G forcing near the Gulf Coast as a weak short wave or two translate quickly eastward. The ECMWF has very dry air firmly entrenched over the Southeast and most of the Gulf of Mexico. Even if the GFS verified, the GFS MOS PoP is still low so the main effect for our region would be mostly cloudy skies and a slight reduction on high temperatures. Temperatures will warm to above average Friday as the 500 mb ridge peaks over the Southeast. && .AVIATION... UPDATED AT 820 PM All rainfall has ended for the evening, and all sites are currently VFR. Restrictions will be imposed later tonight as MVFR to IFR ceilings overspread all of our terminals. Deterioration will generally start from the east but quickly fill in everywhere by 09z. Ceilings will scatter to VFR at all terminals but KECP by midday. However, MVFR ceiling will return to KTLH and KVLD later in the afternoon as more rain spreads inland from the coast. && .MARINE... UPDATED AT 820 PM Recent buoy obs indicated that offshore winds and seas during the mid-eve period were running at marginal advisory level conditions. They should drop below advisory levels during the predawn hours but remain at high end cautionary levels offshore into Saturday evening. Winds and seas will subside Sunday and Monday as the pressure gradient loosens near the cold front. Winds and seas will increase Monday night behind the cold front. && .FIRE WEATHER... No immediate fire weather concerns as relative humidity values will remain above critical levels through Monday. Drier air will begin to arrive on Tuesday, though RH levels should stay above red flag values. && .HYDROLOGY... Rainfall totals for the remainder of today will be negligible. The next rain event (associated with the cold front Sunday and Monday) will produce 0.5 to 0.75 inches across much of the forecast area. This will be far below local Flash Flood Guidance, so the threat of flash flooding and/or riverine flooding is minimal. && .PRELIMINARY POINT TEMPS/POPS... Tallahassee 57 74 66 76 66 / 20 20 20 40 70 Panama City 60 73 68 77 69 / 20 30 20 50 70 Dothan 53 72 65 77 65 / 30 20 20 60 70 Albany 52 74 64 78 66 / 30 20 20 50 70 Valdosta 55 75 64 78 66 / 20 20 20 40 70 Cross City 59 77 65 80 67 / 70 30 20 30 50 Apalachicola 62 73 69 76 69 / 30 30 20 40 70 && .TAE WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AL...None. GM...SMALL CRAFT ADVISORY until 4 AM EST Saturday for Waters from Suwannee River to Apalachicola FL from 20 to 60 NM-Waters from Apalachicola to Destin FL from 20 to 60 NM. && $$ NEAR TERM...Block/Lahr SHORT TERM...Fournier LONG TERM...Fournier AVIATION...Harrigan MARINE...Block/Lahr FIRE WEATHER...Godsey HYDROLOGY...Fournier/Block
AREA FORECAST DISCUSSION...UPDATED
NWS TOPEKA KS
652 PM CST Fri Nov 15 2013 ...Update to aviation forecast discussion... .SHORT TERM...(This Evening through Saturday) Issued at 250 PM CST FRI NOV 15 2013 On Friday afternoon, an upper trough was located over southern California and Nevada while a series of weaker lead short wave troughs were moving through fairly fast west southwest flow aloft from the four counters into the western Plains. At the surface, low pressure was deepening in eastern Colorado with intensifying pressure gradient and southerly flow from southern Texas through the Dakotas. A pool of quality low level moisture was in place across northeast Texas and moving into eastern Oklahoma. As the lee surface low continues to deepen overnight, expect a strong low level jet to transport this moisture into eastern Kansas with a west to east gradient while a strong elevated mixed layer and warm advection builds above the moist boundary layer. The moist advection will likely occur after a fairly quick evening cool down owing to mostly clear skies, and the influx of moisture into cooler air along with fairly strong ascent overnight and dry air aloft may contribute to periods of drizzle during the early morning hours. There are also some indications of moistening around 10 thousand feet which may lead to weak elevated instability and at least some potential for a few showers given the magnitude of lift. Winds at the surface will also increase through the night as the pressure gradient strengthens. Any light shower activity and drizzle will likely come to an end by late Saturday morning as boundary layer mixing increases and elevated capping increases. As mixing increases, the low level jet will begin to mix gusts to the surface. The LLJ is forecast to have 50+ kt winds at 2500 feet AGL which would easily translate 45+ mph wind gusts to the surface on a clear day, but the stratus deck may be sufficient to limit overall mixing a bit, and by the time clearing is forecast to occur, the LLJ will have weakened a bit. The main question today is whether the depth of mixing will matter given the strength of winds even 1500 feet AGL and the very strong late morning pressure gradient. For now, have not issued a wind advisory, but could certainly see the need to do so if future model guidance suggests the 12Z NAM and recent RAP runs that highlight an even stronger low level wind field. It`s a low confidence wind forecast at this time that could result in peak gusts somewhere between 40 mph and 55 mph, with the strongest winds focused in east central KS. By late afternoon, another lead short wave will approach the area. At least partial afternoon clearing should have occurred with temperatures in the lower 70s and dewpoints in the upper 50s. While a strong capping inversion will be in place for much of the day, it appears that the incoming trough will help cool the cap such that afternoon CINH may decrease into the 10 to 50 J/KG range for a short period between roughly 3 PM and 7 PM before rapidly increasing again. Higher Res model guidance suggests MLCAPE in the 500 to 1000 J/KG range during this period while 0-6 km shear is 40 to 60 kts. While these conditions would normally suggest some potential for a few strong storms, the primary limiting factor...even with the incoming short wave trough...is a general lack of any meaningful surface convergence with the southwesterly low level wind field. The lack of low level forcing along with a lopsided shear/CAPE balance suggests it will be difficult to sustain any updrafts. At this time, will maintain a slight chance of thunderstorms in the eastern parts of KS generally east of Marysville to Burlington, and if one should develop it would warrant an attentive eye. .LONG TERM...(Saturday Night through Friday) Issued at 250 PM CST FRI NOV 15 2013 By Saturday evening as the boundary layer begins to cool the southwesterly low level jet increases which will ultimately strengthen the capping inversion. The increasing low level jet during the evening forces drier air into the lower levels. If an elevated storm is able to form after sunset the dry air intrusion should hinder any persistence. All of these factors should work against any sustained storm threat across the area...therefore went with a dry forecast after 00z Sun. Gusty winds continue for the southeast half of the cwa and especially southeast of the turnpike overnight Saturday into Sunday. Low temperatures range from the mid 40s in north central KS to the mid 50s in east central KS. On Sunday morning the main upper level trough axis passes through the region as well as the associated cold front. The cold front should clear the area by 15z Sun with a significant drop in dew points following the passage. Behind the main trough axis northwesterly flow increases in response to the deepening pressure field across the upper Midwest as the system becomes negatively tilted. Forecast soundings show most locations mixing between 800 to 700 mb especially across central KS where dew points are lower. Red flag criteria is possible Sunday during the day across the western portions of the area with winds gusting to around 35 mph in combination with the low relative humidity. Less certain is the effect cooler air behind the front has on temperatures and how low the dew points get Sunday afternoon determining min RH. Therefore did not issue any headlines and will let later shifts evaluate the latest guidance. High temperatures on Sunday look to reach the upper 50s to low 60s. In the wake of that system dry northwest mid level flow sets up for the central US allowing surface high pressure to build into the region. Winds should begin to decrease Sunday evening with a relatively calm day in store for Monday. The mid level flow quickly transitions to a zonal pattern and return flow develops as the high pressure retreats then the models really start to disagree by mid week. The 12z ECMWF/GEM suggesting precip chances by Wed as a shortwave pushes a front through the region, but this lacks any consistency at this point therefore kept the forecast dry. Although the better chances for precip appear to be on Thurs and Fri as a trough approaches from the west coast. The evolution of that system and the associated surface features is unknown. Have added the possibility of snow Thurs night and Friday which is advertised by the 12z ECMWF but confidence is pretty low. Through the extended temperatures remain near average with highs in the 50s and lows in the 30s with a cooling trend late in the period. && .AVIATION...(For the 00Z TAFs through 00Z Saturday Evening) Issued at 643 PM CST FRI NOV 15 2013 Expecting vfr conditions to give way to MVFR/IFR cigs in stratus in the 06z-09z time frame (earlier at KTOP/KFOE) and persist through 14z before scattering to vfr at KMHK with vfr conditions not working into the KTOP/KFOE until 18z. With the degree of moisture advection into the cool air...could see fog and some patchy drizzle as well. Otherwise expect most precip to remain south and east of the TAF sites through the fcst...with gusty south/southwest winds of 20-30 gusts to 35kts slowly decreasing aft 22Z. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Barjenbruch LONG TERM...Sanders AVIATION...63
AREA FORECAST DISCUSSION
NWS GOODLAND KS
158 PM MST THU NOV 14 2013 .SHORT TERM...(THIS AFTERNOON THROUGH FRIDAY) ISSUED AT 1251 PM MST THU NOV 14 2013 LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOW SHORTWAVE TROUGH ACROSS WESTERN KS. SUBSIDENCE/DRYING ASSOCIATED WITH SHORTWAVE RIDGE IMMEDIATELY BEHIND THE TROUGH AXIS IS SPREADING EAST OVER OUR CWA. ANOTHER SHORTWAVE TROUGH IS IN PLACE ACROSS THE PAC NW WITH MID-HIGH LEVEL MOISTURE PLUME OVER THE NORTHERN ROCKIES. AT THE SURFACE A COLD FRONT THAT PUSHED ACROSS OUR CWA THIS MORNING IS NOW OVER CENTRAL KANSAS EXTENDING SOUTH ACROSS THE TEXAS/OKLAHOMA PANHANDLES. SURFACE HIGH PRESSURE IS IN PLACE ACROSS OUR CWA WITH CLEAR SKIES AND SEASONAL TEMPS IN THE MID-UPPER 50S. WITH DRY LAYER AND ONLY PASSING HIGH CLOUDS TO THE NORTH...THE PRIMARY CONCERN IN THE SHORT TERM WILL BE POSSIBLE RFW CONDITIONS ON FRIDAY AFTERNOON. AS SHORTWAVE RIDGE SHIFTS EAST AND UNIDIRECTIONAL SW FLOW DEVELOPS ACROSS CWA WAA WILL BRING ABOVE NORMAL TEMPS BACK TO OUR AREA...ALONG WITH DRY/WINDY CONDITIONS. I FOLLOWED THE PREVIOUS FORECAST TREND AND BUMPED TEMPS UP A LITTLE FRIDAY AFTERNOON...WITH WARMEST TEMPS LIKELY IN THE SOUTHERN PART OF OUR CWA WHERE HIGHS AROUND 70F ARE LIKELY. MODEL SOUNDINGS WOULD INDICATE GOOD MIXING HEIGHTS...SUPPORTING LOW TD VALUES DURING THE AFTERNOON. I WAS CONSERVATIVE IN HOW LOW I WENT...BUT STILL ENDED UP WITH TD VALUES IN THE TEENS ACROSS EASTERN COLORADO. WARM TEMPS AND LOW DEWPOINTS WILL SUPPORT RH VALUES AT LEAST IN THE 15-20 PERCENT RANGE...AND WITH GUSTY WINDS IT LOOKS LIKE WE COULD SEE RFW CRITERIA MET AT LEAST ACROSS THE SW QUADRANT OF OUR CWA. FURTHER NORTH AND EAST I AM NOT AS CONFIDENT IN MEETING CRITERIA. IT IS HARD TO SAY IF WE WILL GET A FULL 3HR OF RFW CRITERIA ACROSS THE SOUTHWEST SO I DECIDED TO START WITH A FIRE WEATHER WATCH DURING THIS FORECAST CYCLE. .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 157 PM MST THU NOV 14 2013 INTI AL CONCERN FOR THE PERIOD WILL CENTER AROUND PRECIPITATION CHANCES AS A SERIES OF LOW AMPLITUDE SHORT WAVE TROUGHS MOVE AROUND THE BASE OF LARGE SCALE TROUGH THAT DIGS INTO THE AREA ON SUNDAY. MODELS SEEM TO BE TRENDING DRIER AND DRIER WITH THESE SYSTEMS AND WITH LATEST SREF AND GEFS DATA BACKING OFF OF POP VALUES...THINK LOWERING POPS TO 10 PERCENT OR LESS WARRANTED AT THIS TIME. AM CONCERNED ABOUT THE PERIOD OF STRONG FRONTAL SCALE FORCING AND POTENTIAL INSTABILITY...BUT WITH DRY PROFILES AND AFOREMENTIONED PROBABILISTIC FORECASTS...DO NOT THINK REALIZATION OF INSTABILITY IS VERY LIKELY TO OCCUR. OTHER CONCERN WILL BE POTENTIAL FOR STRONG WINDS DEVELOPING ACROSS MUCH OF THE AREA ON SUNDAY. MODELS GENERALLY AGREE THAT TIGHT HEIGHT GRADIENT WILL BE IN PLACE ACROSS THE AREA AS TROUGH SAGS TO THE SOUTH...RESULTING IN STRONG WINDS JUST OFF THE SURFACE. AM NOT EXPECTING WARNING LEVEL WINDS...BUT POTENTIAL APPEARS TO BE INCREASING FOR ADVISORY TYPE WINDS IN THE AFTERNOON. IN THE EXTENDED (SUN NIGHT-THURSDAY)...BRIEF PERIOD OF SHORT WAVE RIDGING EXPECTED BEFORE A ZONAL/PROGRESSIVE PATTERN DEVELOPS ACROSS THE AREA THROUGH THE REST OF THE WEEK. DOES NOT APPEAR TO BE MUCH THREAT FOR PRECIPITATION DURING THIS PERIOD...WITH SOMEWHAT PERSISTENT LEE TROUGH LEADING TO PREDOMINATELY WARM SOUTHERLY FLOW. POTENTIAL FOR THICK MOUNTAIN CIRRUS DUE TO STRONG CROSS MOUNTAIN FLOW LIMITS CONFIDENCE ON HOW WARM THINGS WILL GET...BUT CONTINUED WARMING TREND LOOKS TO BE IN ORDER. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 1009 AM MST THU NOV 14 2013 VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD AT BOTH KGLD AND KMCK. GUSTY NORTHEAST WINDS IMMEDIATELY BEHIND COLD FRONT WILL DIMINISH EARLY THIS AFTERNOON...WITH WINDS BECOMING LIGHT AND VARIABLE AS HIGH PRESSURE DEVELOPS INTO THE PLAINS LATE THIS AFTERNOON AND EARLY THIS EVENING AT BOTH TAF SITES. KMCK SHOULD SEE WINDS DIMINISH FIRST WITH GRADIENT ALREADY BEGINNING TO RELAX. WINDS WILL SHIFT TO THE SOUTH OVERNIGHT AS A SURFACE TROUGH DEVELOPS IN EASTERN COLORADO. CURRENTLY EXPECT GUSTY SOUTHERLY WINDS TO DEVELOP AT KGLD AROUND 14Z WITH GUSTS TO 30KT. WINDS LIKELY WONT INCREASE AT KMCK UNTIL AFTER THE CURRENT TAF PERIOD. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...FIRE WEATHER WATCH FROM FRIDAY MORNING THROUGH FRIDAY AFTERNOON FOR KSZ013-027-041. CO...FIRE WEATHER WATCH FROM FRIDAY MORNING THROUGH FRIDAY AFTERNOON FOR COZ253-254. NE...NONE. && $$ SHORT TERM...DR LONG TERM...JRM AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1252 PM MST THU NOV 14 2013 .SHORT TERM...(THIS AFTERNOON THROUGH FRIDAY) ISSUED AT 1251 PM MST THU NOV 14 2013 LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOW SHORTWAVE TROUGH ACROSS WESTERN KS. SUBSIDENCE/DRYING ASSOCIATED WITH SHORTWAVE RIDGE IMMEDIATELY BEHIND THE TROUGH AXIS IS SPREADING EAST OVER OUR CWA. ANOTHER SHORTWAVE TROUGH IS IN PLACE ACROSS THE PAC NW WITH MID-HIGH LEVEL MOISTURE PLUME OVER THE NORTHERN ROCKIES. AT THE SURFACE A COLD FRONT THAT PUSHED ACROSS OUR CWA THIS MORNING IS NOW OVER CENTRAL KANSAS EXTENDING SOUTH ACROSS THE TEXAS/OKLAHOMA PANHANDLES. SURFACE HIGH PRESSURE IS IN PLACE ACROSS OUR CWA WITH CLEAR SKIES AND SEASONAL TEMPS IN THE MID-UPPER 50S. WITH DRY LAYER AND ONLY PASSING HIGH CLOUDS TO THE NORTH...THE PRIMARY CONCERN IN THE SHORT TERM WILL BE POSSIBLE RFW CONDITIONS ON FRIDAY AFTERNOON. AS SHORTWAVE RIDGE SHIFTS EAST AND UNIDIRECTIONAL SW FLOW DEVELOPS ACROSS CWA WAA WILL BRING ABOVE NORMAL TEMPS BACK TO OUR AREA...ALONG WITH DRY/WINDY CONDITIONS. I FOLLOWED THE PREVIOUS FORECAST TREND AND BUMPED TEMPS UP A LITTLE FRIDAY AFTERNOON...WITH WARMEST TEMPS LIKELY IN THE SOUTHERN PART OF OUR CWA WHERE HIGHS AROUND 70F ARE LIKELY. MODEL SOUNDINGS WOULD INDICATE GOOD MIXING HEIGHTS...SUPPORTING LOW TD VALUES DURING THE AFTERNOON. I WAS CONSERVATIVE IN HOW LOW I WENT...BUT STILL ENDED UP WITH TD VALUES IN THE TEENS ACROSS EASTERN COLORADO. WARM TEMPS AND LOW DEWPOINTS WILL SUPPORT RH VALUES AT LEAST IN THE 15-20 PERCENT RANGE...AND WITH GUSTY WINDS IT LOOKS LIKE WE COULD SEE RFW CRITERIA MET AT LEAST ACROSS THE SW QUADRANT OF OUR CWA. FURTHER NORTH AND EAST I AM NOT AS CONFIDENT IN MEETING CRITERIA. IT IS HARD TO SAY IF WE WILL GET A FULL 3HR OF RFW CRITERIA ACROSS THE SOUTHWEST SO I DECIDED TO START WITH A FIRE WEATHER WATCH DURING THIS FORECAST CYCLE. .LONG TERM...(SUNDAY THROUGH THURSDAY) ISSUED AT 1146 PM MST WED NOV 13 2013 SHORTWAVE TROUGH AXIS WILL SWING THROUGH ON SUNDAY...BUT MODELS CONTINUE TO TREND DOWNWARD WITH PRECIPITATION CHANCES. WILL NOT REMOVE POPS ENTIRELY BUT WILL ONLY CARRY SLIGHT TO LOW CHANCE POPS FOR RAIN OR RAIN/SNOW IN THE SUNDAY AND SUNDAY NIGHT PERIOD. THE OTHER MAJOR MODEL TREND HAS BEEN TO BUILD A STRONGER RIDGE BEHIND THAT SYSTEM WHICH WILL DOMINATE THE REMAINDER OF THE LONG TERM PERIOD. WARMED UP TEMPERATURES AS MUCH AS ISC ALLOWED...PROBABLY NOT ENOUGH...FOR THE MONDAY THROUGH THURSDAY PERIOD. NO PRECIPITATION IS EXPECTED AFTER SUNDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 1009 AM MST THU NOV 14 2013 VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD AT BOTH KGLD AND KMCK. GUSTY NORTHEAST WINDS IMMEDIATELY BEHIND COLD FRONT WILL DIMINISH EARLY THIS AFTERNOON...WITH WINDS BECOMING LIGHT AND VARIABLE AS HIGH PRESSURE DEVELOPS INTO THE PLAINS LATE THIS AFTERNOON AND EARLY THIS EVENING AT BOTH TAF SITES. KMCK SHOULD SEE WINDS DIMINISH FIRST WITH GRADIENT ALREADY BEGINNING TO RELAX. WINDS WILL SHIFT TO THE SOUTH OVERNIGHT AS A SURFACE TROUGH DEVELOPS IN EASTERN COLORADO. CURRENTLY EXPECT GUSTY SOUTHERLY WINDS TO DEVELOP AT KGLD AROUND 14Z WITH GUSTS TO 30KT. WINDS LIKELY WONT INCREASE AT KMCK UNTIL AFTER THE CURRENT TAF PERIOD. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...FIRE WEATHER WATCH FROM FRIDAY MORNING THROUGH FRIDAY AFTERNOON FOR KSZ013-027-041. CO...FIRE WEATHER WATCH FROM FRIDAY MORNING THROUGH FRIDAY AFTERNOON FOR COZ253-254. NE...NONE. && $$ SHORT TERM...DR LONG TERM...024 AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1151 PM MST WED NOV 13 2013 .SHORT TERM...(THIS AFTERNOON THROUGH THURSDAY) ISSUED AT 1228 PM MST WED NOV 13 2013 LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOWS SERIES OF SHORTWAVE RIDGES AND TOUGHS FROM MISSISSIPPI VALLEY TO PACIFIC NORTHWEST WITH ACTIVE ZONAL PATTERN ACROSS THE CONUS. THERE IS A SHORTWAVE TROUGH IS PLACE OVER SOUTHERN NEBRASKA EXTENDING SOUTH TO NORTHERN TEXAS...HOWEVER THERE IS LARGE SCALE DRY AIR MASS EVIDENT ON WV IMAGERY. A MOIST MID-UPPER LEVEL MOISTURE PLUME IS IN PACE ACROSS THE CENTRAL ROCKIES AHEAD OF THE NEXT SHORTWAVE TROUGH IN THE UPPER FLOW...WHICH IS CURRENTLY LOCATED ACROSS IDAHO. AT THE SURFACE A TROUGH OF LOW PRESSURE IS IN PLACE ACROSS EASTERN COLORADO WITH SW GRADIENT OVER CENTRAL KANSAS. TO THE WEST VERY LOW TD VALUES HAVE MIXED TO THE SURFACE WITH -4F TO 5F TD VALUES REPORTED ALONG THE FRONT RANGE AND EASTERN PLAINS OF COLORADO. LUCKILY WITH GRADIENT WELL EAST AND WEAK FLOW ALOFT WINDS HAVE BEEN LIGHT AND RFW CRITERIA IS NOT BEING MET. THE SHORTWAVE UPSTREAM OVER THE NW US WILL MOVE EAST THROUGH THURSDAY ACROSS THE NORTHERN PLAINS...KICKING A COLD FRONT SOUTH ACROSS THE PLAINS AFTER MIDNIGHT TONIGHT. WITH VERY DRY AIR MASS IN PLACE I AM ONLY ANTICIPATING THICK HIGH CLOUD COVER AND POSSIBLE BREEZY WINDS BEHIND THE FRONT LATE TONIGHT THROUGH THURSDAY MORNING. THESE CONDITIONS SHOULD HOLD OVERNIGHT TEMPS ABOVE FREEZING (MID TO UPPER 30S) DESPITE DECENT CAA BEHIND COLD FRONT. AFTER A MILD DAY TODAY WE WILL BE LOOKING AT HIGHS CLOSER TO SEASONAL NORMALS ON THURSDAY WITH VALUES RANGING FROM THE LOW TO UPPER 50S. .LONG TERM...(SUNDAY THROUGH THURSDAY) ISSUED AT 1146 PM MST WED NOV 13 2013 SHORTWAVE TROUGH AXIS WILL SWING THROUGH ON SUNDAY...BUT MODELS CONTINUE TO TREND DOWNWARD WITH PRECIPITATION CHANCES. WILL NOT REMOVE POPS ENTIRELY BUT WILL ONLY CARRY SLIGHT TO LOW CHANCE POPS FOR RAIN OR RAIN/SNOW IN THE SUNDAY AND SUNDAY NIGHT PERIOD. THE OTHER MAJOR MODEL TREND HAS BEEN TO BUILD A STRONGER RIDGE BEHIND THAT SYSTEM WHICH WILL DOMINATE THE REMAINDER OF THE LONG TERM PERIOD. WARMED UP TEMPERATURES AS MUCH AS ISC ALLOWED...PROBABLY NOT ENOUGH...FOR THE MONDAY THROUGH THURSDAY PERIOD. NO PRECIPITATION IS EXPECTED AFTER SUNDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1025 PM MST WED NOV 13 2013 VFR CONDITIONS WILL CONTINUE FOR KGLD AND KMCK FOR THE NEXT 24 HOURS. SOUTHWEST WIND WILL SHIFT TO THE NORTHWEST OVERNIGHT AS A SURFACE TROUGH SHIFTS EAST OF THE AREA AND HIGH PRESSURE FILTERS IN BEHIND A COLD FRONT. WINDS WILL BE GUSTY AT TIMES ALONG AND BEHIND THE FRONT AND THEN BECOME LIGHT BY THURSDAY AFTERNOON/EVENING. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...DR LONG TERM...024 AVIATION...FS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1029 PM MST WED NOV 13 2013 .SHORT TERM...(THIS AFTERNOON THROUGH THURSDAY) ISSUED AT 1228 PM MST WED NOV 13 2013 LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOWS SERIES OF SHORTWAVE RIDGES AND TOUGHS FROM MISSISSIPPI VALLEY TO PACIFIC NORTHWEST WITH ACTIVE ZONAL PATTERN ACROSS THE CONUS. THERE IS A SHORTWAVE TROUGH IS PLACE OVER SOUTHERN NEBRASKA EXTENDING SOUTH TO NORTHERN TEXAS...HOWEVER THERE IS LARGE SCALE DRY AIR MASS EVIDENT ON WV IMAGERY. A MOIST MID-UPPER LEVEL MOISTURE PLUME IS IN PACE ACROSS THE CENTRAL ROCKIES AHEAD OF THE NEXT SHORTWAVE TROUGH IN THE UPPER FLOW...WHICH IS CURRENTLY LOCATED ACROSS IDAHO. AT THE SURFACE A TROUGH OF LOW PRESSURE IS IN PLACE ACROSS EASTERN COLORADO WITH SW GRADIENT OVER CENTRAL KANSAS. TO THE WEST VERY LOW TD VALUES HAVE MIXED TO THE SURFACE WITH -4F TO 5F TD VALUES REPORTED ALONG THE FRONT RANGE AND EASTERN PLAINS OF COLORADO. LUCKILY WITH GRADIENT WELL EAST AND WEAK FLOW ALOFT WINDS HAVE BEEN LIGHT AND RFW CRITERIA IS NOT BEING MET. THE SHORTWAVE UPSTREAM OVER THE NW US WILL MOVE EAST THROUGH THURSDAY ACROSS THE NORTHERN PLAINS...KICKING A COLD FRONT SOUTH ACROSS THE PLAINS AFTER MIDNIGHT TONIGHT. WITH VERY DRY AIR MASS IN PLACE I AM ONLY ANTICIPATING THICK HIGH CLOUD COVER AND POSSIBLE BREEZY WINDS BEHIND THE FRONT LATE TONIGHT THROUGH THURSDAY MORNING. THESE CONDITIONS SHOULD HOLD OVERNIGHT TEMPS ABOVE FREEZING (MID TO UPPER 30S) DESPITE DECENT CAA BEHIND COLD FRONT. AFTER A MILD DAY TODAY WE WILL BE LOOKING AT HIGHS CLOSER TO SEASONAL NORMALS ON THURSDAY WITH VALUES RANGING FROM THE LOW TO UPPER 50S. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 136 PM MST WED NOV 13 2013 THE MAIN LONG TERM FORECAST CONCERN IS STILL THE POSSIBILITY OF PRECIPITATION BETWEEN SATURDAY NIGHT AND SUNDAY NIGHT. DRY CONDITIONS AND MID TEMPERATURES WITH PERIODIC INCREASES AND DECREASES IN MOSTLY HIGH CLOUDS ARE EXPECTED FROM THURSDAY NIGHT THROUGH SATURDAY AS A SERIES OF FRAGMENTED LEE TROUGHS ACCOMPANY A SERIES OF UPPER SHORT WAVE TROUGHS ACROSS THE CENTRAL HIGH PLAINS REGION. BY SATURDAY NIGHT...THE MAIN UPPER TROUGH DIVES FROM THE PACIFIC NORTHWEST INTO THE INTERMOUNTAIN REGION AND EMERGES EAST OF THE ROCKIES ACROSS THE NORTHERN AND CENTRAL PLAINS ON SUNDAY. THE MAIN FRONT MOVES THROUGH THE FORECAST AREA BY LATE SATURDAY WITH THE COLDER AIR BEHIND THE FRONT TO MOVE INTO THE CENTRAL HIGH PLAINS REGION SATURDAY NIGHT AND SUNDAY. CURRENTLY EXPECT A RAIN/SNOW MIX TO MOVE INTO THE FORECAST AREA FROM THE NORTHWEST ON SATURDAY NIGHT. THIS MIX WILL CHANGE OVER TO LIGHT RAIN DURING THE DAY ON SUNDAY BEFORE CHANGING OVER TO LIGHT SNOW SUNDAY EVENING AS PRECIPITATION ALSO BEGINS TO TAPER OFF FROM WEST TO EAST SUNDAY NIGHT. DRY CONDITIONS ARE EXPECTED DURING THE FIRST PART OF NEXT WEEK ALONG WITH COOLER THAN AVERAGE TEMPERATURES AS A SURFACE HIGH PRESSURE AREA MOVES INTO THE PLAINS STATES WITH A RIDGE OF HIGHER PRESSURE MOVING IN FROM THE WEST. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1025 PM MST WED NOV 13 2013 VFR CONDITIONS WILL CONTINUE FOR KGLD AND KMCK FOR THE NEXT 24 HOURS. SOUTHWEST WIND WILL SHIFT TO THE NORTHWEST OVERNIGHT AS A SURFACE TROUGH SHIFTS EAST OF THE AREA AND HIGH PRESSSURE FILTERS IN BEHIND A COLD FRONT. WINDS WILL BE GUSTY AT TIMES ALONG AND BEHIND THE FRONT AND THEN BECOME LIGHT BY THURSDAY AFTERNOON/EVENING. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...DR LONG TERM...LOCKHART AVIATION...FS
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1113 PM CST Wed Nov 13 2013 .UPDATE... Issued at 1113 PM CST WED NOV 13 2013 The latest RAP and NAM solutions show the pressure gradient remaining up through the night across eastern KS. Because of this and with recent OBS showing some gusts near 20 KTS, have updated the min temps to bump them up due to continued mixing of the boundary layer. There are two concerns. One is that I may not be warm enough across east central KS where winds are most likely to remain in the 10 to 15 MPH range overnight. The second is across north central KS where the surface trough may move in just before sunrise and allow the boundary layer to decouple and temps to quickly drop off. However latest OBS across central NEB show that temps have not be inclined to cool rapidly once the winds weaken, possibly due to the increasing cloud cover from the approaching upper wave. Because of this opted to keep lows at CNK (notorious for keeping a wind through the night) in the middle 30s. && .SHORT TERM...(This Evening through Thursday) Issued at 249 PM CST WED NOV 13 2013 Little in the way of significant forecast problems for tonight and Thursday. Sig pressure gradient between high over the southern Mississippi valley and low pressure developing in the lee of the Rockies has lead to gusty southerly winds today. These winds will diminish late afternoon and early evening but maintain about 10 kts overnight...keeping temperatures from falling below the upper 20s to lower 30s. Water vapor loop overlaid with RAP analysis and national radar show precipitation associated with low amplitude shortwave trough crossing the northern Rockies. This trough is forecast by all models to move east across the northern U.S., approaching the western Great Lakes by Thursday evening. Greatest forcing aloft and any chance of measurable precipitation with this system is forecast to stay well north of Kansas. Trailing surface low pressure trough along with thicker mid and high level clouds should move into north central and northeast Kansas Thursday afternoon. Thus...afternoon winds on Thursday should not be as strong as those occurring today. .LONG TERM...(Thursday Night through Wednesday) Issued at 249 PM CST WED NOV 13 2013 Focus of the longer term remains on the evolution of the storm system into the weekend. Sfc low development will occur Friday night into Saturday across western KS/NE as the first of two main waves move through the longwave trough and into the plains. WAA and lift should aid in the development of showers and perhaps isolated thunderstorms later Friday night and into Saturday. Low level winds veer in wake of the initial wave later Saturday Saturday night so precip chcs appear sct at best during Sat night. The second and main shortwave will emerge by Sunday along with the associated sfc low. The low will track into Wisconsin later Sunday with the cold front forecast to sweep through the area during the day. The second upper wave remains progressive so don`t expect much in the way of additional precip Sunday into Sunday night although CAA along with shallow lift could result in light rain showers/drizzle or some snow flurries later Sunday night. All in all the ECMWF has trended less amplified with the pattern into next week and as a result is not as cold while GFS remains colder. In any case, it appears colder than avg for early next week then moderating with dry/quiet weather after Sunday night. && .AVIATION...(For the 06Z TAFs through 06Z Thursday Night) Issued at 1113 PM CST WED NOV 13 2013 Limited moisture should allow for dry weather with VFR conditions in spite of a weak upper level wave moving overhead late tonight and Thursday. A surface trough axis is expected to remain west of MHK so the forecast does not anticipate a wind shift prior to 06Z. && .TOP WATCHES/WARNINGS/ADVISORIES...NONE. && $$ UPDATE...Wolters SHORT TERM...GDP LONG TERM...Omitt AVIATION...Wolters
AREA FORECAST DISCUSSION...UPDATED
NWS PITTSBURGH PA
1003 PM EST FRI NOV 15 2013 .SYNOPSIS... MILD WEATHER IS EXPECTED SATURDAY BEFORE A COLD FRONT CROSSES THE REGION SUNDAY NIGHT. SHOWERS AND THUNDERSTORMS WITH STRONG WINDS WILL BE POSSIBLE SUNDAY AND SUNDAY NIGHT. COLD AIR RETURNS TO THE AREA MID-WEEK. && .NEAR TERM /THROUGH SATURDAY/... SLGT ADJUSTMENTS MADE TO POP/WX GRIDS TO REFLECT ONGOING CVRG OF SHWRS AND XPCD MVMT OF THESE SHWRS. NO SGFNT CHGS TO TIMING. PREV DISCUSSION FOLLOWS... PCPN IS BLOSSOMING ACRS SRN OH AND WV IN ASSOCIATION WITH SHRTWV TROF EVIDENT OVER ERN KY BASED ON WATER VAPOR IMAGERY. THIS WAVE WILL MOVE ENEWD ACRS SRN PORTIONS OF FCST AREA...WHERE PREV POPS WERE FOCUSED. POPS WERE INCRD TO CATEGORICAL FOR LGT RAIN ACCUMS. AS NOTED IN PREV FCST...CLDS WILL MAINTAIN ELEVATED MINIMA TNGT WITH PSBL EXCEPTION OF FAR NRN ZONES...WHICH WILL DROP TO NR FRZG. OTHERWISE...MID-UPR 30S WILL BE COMMON OVNGT. H5 RDGG XPCD TO DOMINATE ON SAT. SOME MRNG LOW CLDS PSBL GIVEN XPCD INCRG LOW-LVL MSTR RESULTING FROM SHRTWV TROF PASSAGE. MID- AND UPR-LVL CLDS WILL LMT INSOLATION SOMEWHAT...WITH MAXIMA XPCD TO REACH UPR 50S-NR 60 IN SVRL SPOTS. NO SGFNT WX XPCD ON SAT. PREV DISCUSSION FOLLOWS... A SOUTHERN STREAM SHORTWAVE MOVING ACROSS THE MID ATLANTIC STATES WILL INCREASE CLOUDS THIS EVENING...WITH SHOWERS DEVELOPING MAINLY SOUTH OF I-70 AND IN THE FAR SOUTHEAST RIDGES OVERNIGHT. DRY LOW LEVELS WILL LIMIT RAINFALL AMOUNTS BUT KEPT THE LIKELY POPS FROM PREVIOUS FORECAST ACROSS GARRETT...TUCKER...AND PRESTON COUNTIES BUT WILL BE A HIGH POP LOW QPF EVENT. WITH CLOUDS MOVING IN TEMPERATURES WILL BE HELD UP IN THE UPPER 30S FAR NORTH TO LOWER TO MID 40S SOUTH. SYSTEM WILL QUICKLY EXIT SATURDAY WITH SOUTHWEST FLOW DEVELOPING ALOFT AND TEMPERATURES WARMING INTO THE 50S AND OVER 60 ACROSS THE SOUTH ALONG WITH AT LEAST PARTLY SUNNY SKIES. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/... FLOW ALOFT WILL BCM SWLY AS UPR RDG SHIFTS EWD AND POTENT SHRTWV TROF DIGS INTO THE NRN PLNS. IN RESPONSE TO DPNG SFC CYCLONE... H9 LOW-LVL JET OF 30-50 KT WILL ADVCT MSTR NWD AS FAR AS GRTLKS RGN. MODELS SUGGEST A LEAD SHRTWV TROF WILL IMPACT THE FCST AREA SAT NGT AND MAY GENERATE WDSPRD SHWRS FUELED BY THIS MSTR. WITH ALL MODELS DEPICTING THIS SCENARIO...MAINTAINING DRY FCST DID NOT SEEM PRUDENT. SO POPS WERE ADJUSTED CONSIDERABLY LATE SAT NGT AND SUN MRNG. CLD CVR WILL BE ABUNDANT SUN MRNG OWING TO PSBL ONGOING SHWRS. BUT CVRG OF PCPN AND CLDS WILL WANE BY LATE SUN MRNG AS LEAD WAVE EXITS. THUS...MODEST INSOLATION XPCD SUN AFTN WITH MAXIMA REACHING MID TO UPR 60S. THERE MAY BE A LULL IN PCPN EARLY SUN AFTN AS ATMOSPHERE RECOVERS. BY LATE SUN AFTN...FORCING FOR ASCENT ASSOCIATED WITH THE PRIMARY SHRTWV TROF WILL BGN TO SPREAD ACRS FCST AREA. SLGTLY UNSTABLE ATMOSPHERE WILL BE WEAKLY-CAPPED...BUT SHEAR WILL BE EXTREME AND LKLY WILL OVERCOME ANY DEFICIENCIES IN INSTBY. PRIMARY FOCUS FOR SHWRS AND TSTMS WILL BE ALONG SFC TROF/EVENTUAL CDFNT...WHICH WILL CROSS THE RGN SUN EVE. CELLULAR CNVCTN MAY DVLP AHEAD OF THIS BNDRY...WITH STORM-RELATIVE INFLOW XPCD TO BE QUITE RICH IN STREAMWISE VORTICITY GIVEN FCSTD HODOGRAPHS. AS A RESULT... SCT LOW-TOPPED ROTATING TSTMS WILL BE PSBL LATE SUN AFTN-SUN EVE BEFORE THE ARRIVAL OF THE CDFNT. THE POTL FOR THE PRE-FRONTAL TSTMS IS CONDITIONAL UPON DVLPMT OF MODEST INSTBY IN WARM SECTOR. WITH STRONG FORCING...WEAK INSTBY AND BULK SHEAR PARALLEL TO SFC TROF...STORMS ALONG SFC TROF/CDFNT WILL BCM INCRGLY LINEAR THRU SUN EVE. QUASI-LINEAR CNVCTV SYSTEM XPCD TO ENSUE AS THE BNDRY MOVES EWD THRU THE EVE...AND WILL BE CAPABLE OF DMGG WIND GUSTS AND QLCS MESOVORTEX TORNADOES. FCSTD SHEAR IS EXTREME...AND HODOGRAPHS VERY FAVORABLE...FOR A SVR WX EPISODE LATE SUN AFTN THRU SUN EVE. ALL ZONES WILL SEE PCPN SUN NGT AS THE LINE CROSSES THE RGN. POPS WERE INCRD TO 100 PCT WITH THE PASSAGE OF THE BNDRY. BNDRY XPCD TO CLR THE FCST AREA BY MRNG WITH PSBLY CLR SKIES AT SUNRISE. PREV DISCUSSION FOLLOWS... MILD SATURDAY NIGHT AS CLOUDS AND DEEP MOISTURE INCREASE AHEAD OF A STRONG STORM SYSTEM DEVELOPING ACROSS THE NORTHERN PLAINS AND HEADING INTO THE NORTHERN GREAT LAKES SUNDAY. COLD FRONT WILL APPROACH THE REGION BY LATE DAY SUNDAY AND CROSS SUNDAY NIGHT WITH SHOWERS AND POSSIBLE THUNDERSTORMS. SHOWERS WILL BE INCREASING AS THE DAY PROGRESSES SUNDAY WITH SOUTH WINDS GUSTING OVER 30 MPH BY AFTERNOON. SYSTEM SUNDAY NIGHT LOOKS TO BE REMINISCENT OF HALLOWEEN COLD FRONT WITH A POSSIBLE CONVECTIVE LINE ALONG THE FRONT BRINGING DOWN WINDS FROM A LOW LEVEL JET APPROACHING 70KTS. HAVE HIGHLIGHTED THE POTENTIAL FOR DAMAGING WINDS IN THE HWO. FRONT EXITS EAST BY SUNRISE MONDAY WITH COLD ADVECTION DURING THE DAY. COLDEST AIR LAGS THE FRONT SO A DRY PERIOD EARLY WILL GIVE WAY TO SOME LAKE ENHANCED SHOWERS AND UPSLOPE BY AFTERNOON AS TEMPERATURES RECOVER LITTLE FROM MORNING READINGS. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... AN UPR TROF COMBINED WITH NW FLOW ACRS THE GT LKS WL CONT PCPN CHCS INTO TUE. WITH COLD AIR ADVCTN ANY RAIN SHOULD CHG TO SNW MON NGT. HIGH PRES AND WRM AIR ADVCTN SHOULD END ANY PCPN BY LT TUE...WITH DRY WEA AND SLOWLY WRMG TEMPS CONTG THRU THE END OF THE WK. && .AVIATION /03Z SATURDAY THROUGH WEDNESDAY/... WEAK TROUGH PASSING OVER THE AREA TONIGHT COULD RESULT IN PERIODS OF LIGHT SHOWERS PRIMARILY SOUTH OF PITTSBURGH...BUT OPTED NOT TO INCLUDE IN THE 00Z TAF PACKAGE FOR KMGW OR KZZV AS EXPECT COVERAGE TO BE SCATTERED AND DURATION...IF ANY...BRIEF. VFR CONDS EXPECTED OVERNIGHT...BUT LATEST RUC SOUNDINGS INDICATE THE POTENTIAL FOR MVFR CLOUD COVERAGE BY MORNING BETWEEN 11Z AND 12Z. VFR CONDTIONS THEN EXPECTED AREAWIDE BY LATE MORNING. .OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/... RSTRNS ALG WITH A PD OF LLWS AND GUSTY WNDS ARE EXPD WITH THE APCH AND PASSAGE OF A STG CDFNT SUN AND SUN NGT. RSTRNS WL REMAIN PSBL THRU ERLY TUE AS AN UPR TROF CROSSES THE GT LKS IN NW FLOW. BLDG HIGH PRES RTNS VFR CONDS LT TUE. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$ UPDATES...KRAMAR
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
851 PM EST FRI NOV 15 2013 .SYNOPSIS... MILD WEATHER IS EXPECTED SATURDAY BEFORE A COLD FRONT CROSSES THE REGION SUNDAY NIGHT. SHOWERS AND THUNDERSTORMS WITH STRONG WINDS WILL BE POSSIBLE SUNDAY AND SUNDAY NIGHT. COLD AIR RETURNS TO THE AREA MID-WEEK. && .NEAR TERM /THROUGH SATURDAY/... PCPN IS BLOSSOMING ACRS SRN OH AND WV IN ASSOCIATION WITH SHRTWV TROF EVIDENT OVER ERN KY BASED ON WATER VAPOR IMAGERY. THIS WAVE WILL MOVE ENEWD ACRS SRN PORTIONS OF FCST AREA...WHERE PREV POPS WERE FOCUSED. POPS WERE INCRD TO CATEGORICAL FOR LGT RAIN ACCUMS. AS NOTED IN PREV FCST...CLDS WILL MAINTAIN ELEVATED MINIMA TNGT WITH PSBL EXCEPTION OF FAR NRN ZONES...WHICH WILL DROP TO NR FRZG. OTHERWISE...MID-UPR 30S WILL BE COMMON OVNGT. H5 RDGG XPCD TO DOMINATE ON SAT. SOME MRNG LOW CLDS PSBL GIVEN XPCD INCRG LOW-LVL MSTR RESULTING FROM SHRTWV TROF PASSAGE. MID- AND UPR-LVL CLDS WILL LMT INSOLATION SOMEWHAT...WITH MAXIMA XPCD TO REACH UPR 50S-NR 60 IN SVRL SPOTS. NO SGFNT WX XPCD ON SAT. PREV DISCUSSION FOLLOWS... A SOUTHERN STREAM SHORTWAVE MOVING ACROSS THE MID ATLANTIC STATES WILL INCREASE CLOUDS THIS EVENING...WITH SHOWERS DEVELOPING MAINLY SOUTH OF I-70 AND IN THE FAR SOUTHEAST RIDGES OVERNIGHT. DRY LOW LEVELS WILL LIMIT RAINFALL AMOUNTS BUT KEPT THE LIKELY POPS FROM PREVIOUS FORECAST ACROSS GARRETT...TUCKER...AND PRESTON COUNTIES BUT WILL BE A HIGH POP LOW QPF EVENT. WITH CLOUDS MOVING IN TEMPERATURES WILL BE HELD UP IN THE UPPER 30S FAR NORTH TO LOWER TO MID 40S SOUTH. SYSTEM WILL QUICKLY EXIT SATURDAY WITH SOUTHWEST FLOW DEVELOPING ALOFT AND TEMPERATURES WARMING INTO THE 50S AND OVER 60 ACROSS THE SOUTH ALONG WITH AT LEAST PARTLY SUNNY SKIES. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/... FLOW ALOFT WILL BCM SWLY AS UPR RDG SHIFTS EWD AND POTENT SHRTWV TROF DIGS INTO THE NRN PLNS. IN RESPONSE TO DPNG SFC CYCLONE... H9 LOW-LVL JET OF 30-50 KT WILL ADVCT MSTR NWD AS FAR AS GRTLKS RGN. MODELS SUGGEST A LEAD SHRTWV TROF WILL IMPACT THE FCST AREA SAT NGT AND MAY GENERATE WDSPRD SHWRS FUELED BY THIS MSTR. WITH ALL MODELS DEPICTING THIS SCENARIO...MAINTAINING DRY FCST DID NOT SEEM PRUDENT. SO POPS WERE ADJUSTED CONSIDERABLY LATE SAT NGT AND SUN MRNG. CLD CVR WILL BE ABUNDANT SUN MRNG OWING TO PSBL ONGOING SHWRS. BUT CVRG OF PCPN AND CLDS WILL WANE BY LATE SUN MRNG AS LEAD WAVE EXITS. THUS...MODEST INSOLATION XPCD SUN AFTN WITH MAXIMA REACHING MID TO UPR 60S. THERE MAY BE A LULL IN PCPN EARLY SUN AFTN AS ATMOSPHERE RECOVERS. BY LATE SUN AFTN...FORCING FOR ASCENT ASSOCIATED WITH THE PRIMARY SHRTWV TROF WILL BGN TO SPREAD ACRS FCST AREA. SLGTLY UNSTABLE ATMOSPHERE WILL BE WEAKLY-CAPPED...BUT SHEAR WILL BE EXTREME AND LKLY WILL OVERCOME ANY DEFICIENCIES IN INSTBY. PRIMARY FOCUS FOR SHWRS AND TSTMS WILL BE ALONG SFC TROF/EVENTUAL CDFNT...WHICH WILL CROSS THE RGN SUN EVE. CELLULAR CNVCTN MAY DVLP AHEAD OF THIS BNDRY...WITH STORM-RELATIVE INFLOW XPCD TO BE QUITE RICH IN STREAMWISE VORTICITY GIVEN FCSTD HODOGRAPHS. AS A RESULT... SCT LOW-TOPPED ROTATING TSTMS WILL BE PSBL LATE SUN AFTN-SUN EVE BEFORE THE ARRIVAL OF THE CDFNT. THE POTL FOR THE PRE-FRONTAL TSTMS IS CONDITIONAL UPON DVLPMT OF MODEST INSTBY IN WARM SECTOR. WITH STRONG FORCING...WEAK INSTBY AND BULK SHEAR PARALLEL TO SFC TROF...STORMS ALONG SFC TROF/CDFNT WILL BCM INCRGLY LINEAR THRU SUN EVE. QUASI-LINEAR CNVCTV SYSTEM XPCD TO ENSUE AS THE BNDRY MOVES EWD THRU THE EVE...AND WILL BE CAPABLE OF DMGG WIND GUSTS AND QLCS MESOVORTEX TORNADOES. FCSTD SHEAR IS EXTREME...AND HODOGRAPHS VERY FAVORABLE...FOR A SVR WX EPISODE LATE SUN AFTN THRU SUN EVE. ALL ZONES WILL SEE PCPN SUN NGT AS THE LINE CROSSES THE RGN. POPS WERE INCRD TO 100 PCT WITH THE PASSAGE OF THE BNDRY. BNDRY XPCD TO CLR THE FCST AREA BY MRNG WITH PSBLY CLR SKIES AT SUNRISE. PREV DISCUSSION FOLLOWS... MILD SATURDAY NIGHT AS CLOUDS AND DEEP MOISTURE INCREASE AHEAD OF A STRONG STORM SYSTEM DEVELOPING ACROSS THE NORTHERN PLAINS AND HEADING INTO THE NORTHERN GREAT LAKES SUNDAY. COLD FRONT WILL APPROACH THE REGION BY LATE DAY SUNDAY AND CROSS SUNDAY NIGHT WITH SHOWERS AND POSSIBLE THUNDERSTORMS. SHOWERS WILL BE INCREASING AS THE DAY PROGRESSES SUNDAY WITH SOUTH WINDS GUSTING OVER 30 MPH BY AFTERNOON. SYSTEM SUNDAY NIGHT LOOKS TO BE REMINISCENT OF HALLOWEEN COLD FRONT WITH A POSSIBLE CONVECTIVE LINE ALONG THE FRONT BRINGING DOWN WINDS FROM A LOW LEVEL JET APPROACHING 70KTS. HAVE HIGHLIGHTED THE POTENTIAL FOR DAMAGING WINDS IN THE HWO. FRONT EXITS EAST BY SUNRISE MONDAY WITH COLD ADVECTION DURING THE DAY. COLDEST AIR LAGS THE FRONT SO A DRY PERIOD EARLY WILL GIVE WAY TO SOME LAKE ENHANCED SHOWERS AND UPSLOPE BY AFTERNOON AS TEMPERATURES RECOVER LITTLE FROM MORNING READINGS. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... AN UPR TROF COMBINED WITH NW FLOW ACRS THE GT LKS WL CONT PCPN CHCS INTO TUE. WITH COLD AIR ADVCTN ANY RAIN SHOULD CHG TO SNW MON NGT. HIGH PRES AND WRM AIR ADVCTN SHOULD END ANY PCPN BY LT TUE...WITH DRY WEA AND SLOWLY WRMG TEMPS CONTG THRU THE END OF THE WK. && .AVIATION /01Z SATURDAY THROUGH WEDNESDAY/... WEAK TROUGH PASSING OVER THE AREA TONIGHT COULD RESULT IN PERIODS OF LIGHT SHOWERS PRIMARILY SOUTH OF PITTSBURGH...BUT OPTED NOT TO INCLUDE IN THE 00Z TAF PACKAGE FOR KMGW OR KZZV AS EXPECT COVERAGE TO BE SCATTERED AND DURATION...IF ANY...BRIEF. VFR CONDS EXPECTED OVERNIGHT...BUT LATEST RUC SOUNDINGS INDICATE THE POTENTIAL FOR MVFR CLOUD COVERAGE BY MORNING BETWEEN 11Z AND 12Z. VFR CONDTIONS THEN EXPECTED AREAWIDE BY LATE MORNING. .OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/... RSTRNS ALG WITH A PD OF LLWS AND GUSTY WNDS ARE EXPD WITH THE APCH AND PASSAGE OF A STG CDFNT SUN AND SUN NGT. RSTRNS WL REMAIN PSBL THRU ERLY TUE AS AN UPR TROF CROSSES THE GT LKS IN NW FLOW. BLDG HIGH PRES RTNS VFR CONDS LT TUE. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$ UPDATE...KRAMAR
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
655 PM EST FRI NOV 15 2013 .SYNOPSIS... A MILD WEEKEND IS IN STORE AFTER A WEAK WEATHER SYSTEM BRINGS CLOUDS...AND A FEW SHOWERS MAINLY SOUTH AND EAST OF PITTSBURGH TONIGHT. A POWERFUL COLD FRONT WILL BRING SHOWERS AND STRONG WINDS SUNDAY AND SUNDAY NIGHT. && .NEAR TERM /THROUGH SATURDAY/... A SOUTHERN STREAM SHORTWAVE MOVING ACROSS THE MID ATLANTIC STATES WILL INCREASE CLOUDS THIS EVENING...WITH SHOWERS DEVELOPING MAINLY SOUTH OF I-70 AND IN THE FAR SOUTHEAST RIDGES OVERNIGHT. DRY LOW LEVELS WILL LIMIT RAINFALL AMOUNTS BUT KEPT THE LIKELY POPS FROM PREVIOUS FORECAST ACROSS GARRETT...TUCKER...AND PRESTON COUNTIES BUT WILL BE A HIGH POP LOW QPF EVENT. WITH CLOUDS MOVING IN TEMPERATURES WILL BE HELD UP IN THE UPPER 30S FAR NORTH TO LOWER TO MID 40S SOUTH. SYSTEM WILL QUICKLY EXIT SATURDAY WITH SOUTHWEST FLOW DEVELOPING ALOFT AND TEMPERATURES WARMING INTO THE 50S AND OVER 60 ACROSS THE SOUTH ALONG WITH AT LEAST PARTLY SUNNY SKIES. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/... MILD SATURDAY NIGHT AS CLOUDS AND DEEP MOISTURE INCREASE AHEAD OF A STRONG STORM SYSTEM DEVELOPING ACROSS THE NORTHERN PLAINS AND HEADING INTO THE NORTHERN GREAT LAKES SUNDAY. COLD FRONT WILL APPROACH THE REGION BY LATE DAY SUNDAY AND CROSS SUNDAY NIGHT WITH SHOWERS AND POSSIBLE THUNDERSTORMS. SHOWERS WILL BE INCREASING AS THE DAY PROGRESSES SUNDAY WITH SOUTH WINDS GUSTING OVER 30 MPH BY AFTERNOON. SYSTEM SUNDAY NIGHT LOOKS TO BE REMINISCENT OF HALLOWEEN COLD FRONT WITH A POSSIBLE CONVECTIVE LINE ALONG THE FRONT BRINGING DOWN WINDS FROM A LOW LEVEL JET APPROACHING 70KTS. HAVE HIGHLIGHTED THE POTENTIAL FOR DAMAGING WINDS IN THE HWO. FRONT EXITS EAST BY SUNRISE MONDAY WITH COLD ADVECTION DURING THE DAY. COLDEST AIR LAGS THE FRONT SO A DRY PERIOD EARLY WILL GIVE WAY TO SOME LAKE ENHANCED SHOWERS AND UPSLOPE BY AFTERNOON AS TEMPERATURES RECOVER LITTLE FROM MORNING READINGS. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... AN UPR TROF COMBINED WITH NW FLOW ACRS THE GT LKS WL CONT PCPN CHCS INTO TUE. WITH COLD AIR ADVCTN ANY RAIN SHOULD CHG TO SNW MON NGT. HIGH PRES AND WRM AIR ADVCTN SHOULD END ANY PCPN BY LT TUE...WITH DRY WEA AND SLOWLY WRMG TEMPS CONTG THRU THE END OF THE WK. && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/... WEAK TROUGH PASSING OVER THE AREA TONIGHT COULD RESULT IN PERIODS OF LIGHT SHOWERS PRIMARILY SOUTH OF PITTSBURGH...BUT OPTED NOT TO INCLUDE IN THE 00Z TAF PACKAGE FOR KMGW OR KZZV AS EXPECT COVERAGE TO BE SCATTERED AND DURATION...IF ANY...BRIEF. VFR CONDS EXPECTED OVERNIGHT...BUT LATEST RUC SOUNDINGS INDICATE THE POTENTIAL FOR MVFR CLOUD COVERAGE BY MORNING BETWEEN 11Z AND 12Z. VFR CONDTIONS THEN EXPECTED AREAWIDE BY LATE MORNING. .OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/... RSTRNS ALG WITH A PD OF LLWS AND GUSTY WNDS ARE EXPD WITH THE APCH AND PASSAGE OF A STG CDFNT SUN AND SUN NGT. RSTRNS WL REMAIN PSBL THRU ERLY TUE AS AN UPR TROF CROSSES THE GT LKS IN NW FLOW. BLDG HIGH PRES RTNS VFR CONDS LT TUE. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
528 AM CST THU NOV 14 2013 .UPDATE... ISSUED AT 523 AM CST THU NOV 14 2013 UPDATED TO INCLUDE 12Z AVIATION DISCUSSION BELOW. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 334 AM CST THU NOV 14 2013 LATEST WATER VAPOR IMAGERY AND RAP UPPER AIR ANALYSES SHOWING POSITIVELY TILTED SHORTWAVE TROUGH EXTENDING FROM MANITOBA SOUTHWEST INTO WYOMING. THIS FEATURE IS MOVING EAST QUICKLY... AND WILL HELP PUSH A COLD FRONT THROUGH THE AREA TODAY. MID-HIGH CLOUDS HAVE BLOSSOMED ALONG/AHEAD OF THE UPPER WAVE AND FRONTAL BOUNDARY... WITH SOME PCPN OCCURRING UP AROUND 8-10K FT AGL OR SO. THERE IS SOME PCPN REACHING THE GROUND OVER SOUTHWEST SOUTH DAKOTA... BUT OVERALL THINGS ARE VIRGA GIVEN THE DRY ANTECEDENT AIRMASS WHICH WAS QUITE APPARENT ON THE KMPX... KABR... AND KOAX 00Z SOUNDINGS. AS THIS SYSTEM PROGRESSES EAST TODAY IT MAY EVENTUALLY MANAGE TO GET SOME PCPN TO THE GROUND. THE 03Z HOPWRF KEEPS MOST OF THE ACTIVITY ALOFT... BUT SUGGEST SOME LIGHT PCPN COULD OCCUR OVER THE FAR SOUTH/EAST PORTIONS OF THE FORECAST AREA THIS MORNING. THE GFS IS THE MOST AMBITIOUS IN GENERATING SOME PCPN... BUT THE ECMWF ALSO PRODUCES SOME. FORCING IS DECENT... WITH A BAND OF DPVA AND SOME UPPER DIVERGENCE... BUT MOISTURE IS THE OBVIOUS MISSING COMPONENT. THE THALER QG DIAGNOSTICS SWING THROUGH MOST OF THE FORCING THIS MORNING... WITH SUBSIDENCE QUICKLY WORKING IN THIS AFTERNOON. SIMPLEST THING TO DO IS TO STAY CLOSE TO THE GOING FORECAST... WHICH INCLUDED SOME LOW CHANCE POPS OVER THE SOUTH/EAST PORTION OF THE AREA THIS MORNING. WILL ALSO MAINTAIN A FEW SMALL POCKETS OF FREEZING PCPN CHANCES EARLY THIS MORNING IN CASE IN PCPN OCCURS WHILE SURFACE TEMPERATURES ARE STILL AOB FREEZING... SINCE CURRENT OBS OVER WEST CENTRAL WISCONSIN SUGGEST SOME LOCAL READINGS ARE DOWN IN THAT AREA. OTHERWISE... WE/LL SEE SLIGHTLY COOLER AIR ARRIVE BEHIND THE FRONT FOR TONIGHT... BUT WILL BE RIGHT BACK INTO RETURN FLOW BY FRIDAY MORNING. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 334 AM CST THU NOV 14 2013 THE MAIN CONCERN IN THE LONGER TERM IS THE PROGRESSION OF THE UPPER TROUGH OVER THE WESTERN U.S. ON FRIDAY TO THE GREAT LAKES BY MONDAY. THE GFS SOLUTION REMAINS THE OUTLIER WITH BASICALLY ONE TROUGH MOVING THROUGH DURING THE WEEKEND. THIS WOULD DRIVE A LOW PRESSURE SYSTEM NORTHEAST ACROSS MN/WI ON SATURDAY/SATURDAY NIGHT WITH A COLD FRONT SWEEPING THROUGH EARLY ON SUNDAY. THE ECWMF AND GEM ARE MORE CONSISTENT WITH THE TROUGH MOVING THROUGH IN TWO PARTS. ONE PIECE OF ENERGY MOVES THROUGH ON SATURDAY WITH THE MAIN TROUGH MOVING THROUGH SUNDAY/SUNDAY NIGHT. THIS YIELDS AN AREA OF LOW PRESSURE MOVING ACROSS MN/WI SATURDAY/SATURDAY NIGHT WITH RAIN LIKELY IN MOST AREAS...ESPECIALLY EASTERN MN/WI. A SECOND LOW THEN RIDES NORTHEAST FROM THE CENTRAL PLAINS TO EASTERN WI FROM SATURDAY NIGHT TO SUNDAY NIGHT. THE LOW/MID LEVEL THERMAL PROFILE FROM THE ECMWF IS TOO WARM FOR MUCH SNOW AT THIS TIME IN MN WITH SOME POTENTIAL FOR ACCUMULATING SNOW IN WESTERN WI SUNDAY NIGHT. THE PROBLEM IS THAT THE COLD AIR IS MOVING IN ABOUT AS FAST AS THE MOISTURE IS LEAVING... SO THERE IS ONLY A SMALL WINDOW OF OPPORTUNITY. IT WILL CERTAINLY TURN WINDY AND COLDER IN THE WAKE OF THE LOW SUNDAY NIGHT AND MONDAY. THE DROP IN HIGHS FROM SUNDAY TO MONDAY STILL LOOKS TO BE ON THE ORDER OF 15 DEGREES OR SO. HIGH PRESSURE MOVES QUICKLY ACROSS THE UPPER MISSISSIPPI VALLEY MONDAY NIGHT WITH A WARMING TREND DEVELOPING ON TUESDAY AND LASTING INTO THE LATTER HALF OF THE WORK WEEK. THE HIGHS FOR TUESDAY AND WEDNESDAY WILL LIKELY NEED TO BE RAISED BY A CATEGORY OR MORE IF THE ECMWF SOLUTION FOR EARLY NEXT WEEK IS MORE ON TARGET THEN THE REST. IN FACT THE ECMX MOS INDICATES MIDDLE 40S FOR TUESDAY AND WEDNESDAY. THE PATTERN DEVELOPING EARLY NEXT WEEK LOOKS MUCH LIKE YESTERDAY (WEDNESDAY). THE MAIN CULPRIT DRAGGING DOWN THE CR EXTEND HIGHS WAS DGEX WITH HIGHS IN THE TEENS AND 20S. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 523 AM CST THU NOV 14 2013 A WEAK SHORTWAVE AND COLD FRONT WILL MOVE THROUGH THE AREA TODAY... BRINGING MAINLY MID-HIGH CLOUDS. SOME CEILINGS AOA 5K FT AGL COULD OCCUR FOR A SHORT TIME ALONG WITH SOME SPRINKLES... BUT THAT SHOULD BE THE EXTENT OF THINGS. WINDS WILL VEER AS THE FRONT MOVES THROUGH... THEN BEGIN TO BACK AGAIN TOWARD THE END OF THE FORECAST PERIOD AS RETURN FLOW SETS BACK UP OVER THE REGION. THERE COULD BE SOME PATCHY FOG LATE TONIGHT... BUT AT THIS POINT IT APPEARS THAT THERE COULD BE ENOUGH CLOUD COVER AROUND TO KEEP IT FROM HAPPENING. HOWEVER... THAT IS SOMETHING THAT WILL NEED TO BE WATCHED IN SUBSEQUENT FORECASTS. KMSP...TAF REFLECTS EXPECTATIONS WITH MINIMAL UNCERTAINTY. THERE COULD BE SLIGHTLY LOWER CEILINGS FOR A SHORT TIME TODAY... BUT THEY WOULD STILL BE VFR. THERE COULD ALSO BE SOME MVFR FOG LATE TONIGHT... BUT CONFIDENCE IS TOO LOW AT THIS POINT TO INCLUDE IN THE TAF. /OUTLOOK FOR KMSP/ FRIDAY AFTERNOON...VFR. SOUTH WIND 5 TO 15 KT. FRIDAY NIGHT...MVFR CEILINGS EXPECTED LATE. IFR CEILINGS AND MVFR VISIBILITIES POSSIBLE WITH A CHANCE OF RAIN. SOUTHEAST WIND 10 TO 20 KT. SATURDAY...MVFR CEILINGS AND VISIBILITIES EXPECTED WITH RAIN... IFR POSSIBLE. SOUTHEAST WIND 15 TO 20 KT. SATURDAY NIGHT...MVFR CEILINGS AND VISIBILITIES EXPECTED WITH RAIN... IFR POSSIBLE. SOUTH WIND 10 TO 20 KT BECOMING SOUTHWEST. SUNDAY...MVFR CEILINGS AND VISIBILITIES POSSIBLE WITH A CHANCE OF RAIN/SNOW... IFR POSSIBLE EARLY. WEST WIND 10 TO 20 KT BECOMING NORTHWEST 15 TO 25 KT. SUNDAY NIGHT...MVFR CEILINGS POSSIBLE EARLY. NORTHWEST WIND 10 TO 20 KT. MONDAY...VFR. NORTHWEST WIND 5 TO 15 KT. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ UPDATE... SHORT TERM... LONG TERM...RAH AVIATION...
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
334 AM CST THU NOV 14 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 334 AM CST THU NOV 14 2013 LATEST WATER VAPOR IMAGERY AND RAP UPPER AIR ANALYSES SHOWING POSITIVELY TILTED SHORTWAVE TROUGH EXTENDING FROM MANITOBA SOUTHWEST INTO WYOMING. THIS FEATURE IS MOVING EAST QUICKLY... AND WILL HELP PUSH A COLD FRONT THROUGH THE AREA TODAY. MID-HIGH CLOUDS HAVE BLOSSOMED ALONG/AHEAD OF THE UPPER WAVE AND FRONTAL BOUNDARY... WITH SOME PCPN OCCURRING UP AROUND 8-10K FT AGL OR SO. THERE IS SOME PCPN REACHING THE GROUND OVER SOUTHWEST SOUTH DAKOTA... BUT OVERALL THINGS ARE VIRGA GIVEN THE DRY ANTECEDENT AIRMASS WHICH WAS QUITE APPARENT ON THE KMPX... KABR... AND KOAX 00Z SOUNDINGS. AS THIS SYSTEM PROGRESSES EAST TODAY IT MAY EVENTUALLY MANAGE TO GET SOME PCPN TO THE GROUND. THE 03Z HOPWRF KEEPS MOST OF THE ACTIVITY ALOFT... BUT SUGGEST SOME LIGHT PCPN COULD OCCUR OVER THE FAR SOUTH/EAST PORTIONS OF THE FORECAST AREA THIS MORNING. THE GFS IS THE MOST AMBITIOUS IN GENERATING SOME PCPN... BUT THE ECMWF ALSO PRODUCES SOME. FORCING IS DECENT... WITH A BAND OF DPVA AND SOME UPPER DIVERGENCE... BUT MOISTURE IS THE OBVIOUS MISSING COMPONENT. THE THALER QG DIAGNOSTICS SWING THROUGH MOST OF THE FORCING THIS MORNING... WITH SUBSIDENCE QUICKLY WORKING IN THIS AFTERNOON. SIMPLEST THING TO DO IS TO STAY CLOSE TO THE GOING FORECAST... WHICH INCLUDED SOME LOW CHANCE POPS OVER THE SOUTH/EAST PORTION OF THE AREA THIS MORNING. WILL ALSO MAINTAIN A FEW SMALL POCKETS OF FREEZING PCPN CHANCES EARLY THIS MORNING IN CASE IN PCPN OCCURS WHILE SURFACE TEMPERATURES ARE STILL AOB FREEZING... SINCE CURRENT OBS OVER WEST CENTRAL WISCONSIN SUGGEST SOME LOCAL READINGS ARE DOWN IN THAT AREA. OTHERWISE... WE/LL SEE SLIGHTLY COOLER AIR ARRIVE BEHIND THE FRONT FOR TONIGHT... BUT WILL BE RIGHT BACK INTO RETURN FLOW BY FRIDAY MORNING. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 334 AM CST THU NOV 14 2013 THE MAIN CONCERN IN THE LONGER TERM IS THE PROGRESSION OF THE UPPER TROUGH OVER THE WESTERN U.S. ON FRIDAY TO THE GREAT LAKES BY MONDAY. THE GFS SOLUTION REMAINS THE OUTLIER WITH BASICALLY ONE TROUGH MOVING THROUGH DURING THE WEEKEND. THIS WOULD DRIVE A LOW PRESSURE SYSTEM NORTHEAST ACROSS MN/WI ON SATURDAY/SATURDAY NIGHT WITH A COLD FRONT SWEEPING THROUGH EARLY ON SUNDAY. THE ECWMF AND GEM ARE MORE CONSISTENT WITH THE TROUGH MOVING THROUGH IN TWO PARTS. ONE PIECE OF ENERGY MOVES THROUGH ON SATURDAY WITH THE MAIN TROUGH MOVING THROUGH SUNDAY/SUNDAY NIGHT. THIS YIELDS AN AREA OF LOW PRESSURE MOVING ACROSS MN/WI SATURDAY/SATURDAY NIGHT WITH RAIN LIKELY IN MOST AREAS...ESPECIALLY EASTERN MN/WI. A SECOND LOW THEN RIDES NORTHEAST FROM THE CENTRAL PLAINS TO EASTERN WI FROM SATURDAY NIGHT TO SUNDAY NIGHT. THE LOW/MID LEVEL THERMAL PROFILE FROM THE ECMWF IS TOO WARM FOR MUCH SNOW AT THIS TIME IN MN WITH SOME POTENTIAL FOR ACCUMULATING SNOW IN WESTERN WI SUNDAY NIGHT. THE PROBLEM IS THAT THE COLD AIR IS MOVING IN ABOUT AS FAST AS THE MOISTURE IS LEAVING... SO THERE IS ONLY A SMALL WINDOW OF OPPORTUNITY. IT WILL CERTAINLY TURN WINDY AND COLDER IN THE WAKE OF THE LOW SUNDAY NIGHT AND MONDAY. THE DROP IN HIGHS FROM SUNDAY TO MONDAY STILL LOOKS TO BE ON THE ORDER OF 15 DEGREES OR SO. HIGH PRESSURE MOVES QUICKLY ACROSS THE UPPER MISSISSIPPI VALLEY MONDAY NIGHT WITH A WARMING TREND DEVELOPING ON TUESDAY AND LASTING INTO THE LATTER HALF OF THE WORK WEEK. THE HIGHS FOR TUESDAY AND WEDNESDAY WILL LIKELY NEED TO BE RAISED BY A CATEGORY OR MORE IF THE ECMWF SOLUTION FOR EARLY NEXT WEEK IS MORE ON TARGET THEN THE REST. IN FACT THE ECMX MOS INDICATES MIDDLE 40S FOR TUESDAY AND WEDNESDAY. THE PATTERN DEVELOPING EARLY NEXT WEEK LOOKS MUCH LIKE YESTERDAY (WEDNESDAY). THE MAIN CULPRIT DRAGGING DOWN THE CR EXTEND HIGHS WAS DGEX WITH HIGHS IN THE TEENS AND 20S. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1111 PM CST WED NOV 13 2013 COLD FRONT OVER THE NORTHERN PLAINS WILL MOVE EAST THROUGH THE FORECAST PERIOD AS AN UPPER LEVEL DISTURBANCE TRACK ALONG THE US/CANADIAN BORDER. MID-HIGH CLOUDS CONTINUE TO EXPAND ALONG/AHEAD OF THESE FEATURES... AND WE SHOULD SEE THEM OVERSPREAD THE AREA OVERNIGHT. SOME LOWER CEILINGS... PERHAPS AOB 5K FT AGL OVER THE EASTERN PORTION OF THE AREA... WILL OCCUR FROM AROUND12-17Z... AND THE FAR EAST/SOUTHEAST COULD SEE SOME LIGHT PCPN AS WELL. HOWEVER... THINGS WILL GENERALLY BE VFR WITH FAIRLY LIGHT WINDS VEERING THROUGH THE PERIOD. KMSP...TAF REFLECTS EXPECTATIONS WITH MINIMAL UNCERTAINTY. THE ONLY REAL QUESTION WOULD BE WHETHER SOME LOWER CEILINGS MANIFEST THEMSELVES THURSDAY MORNING... BUT AT THIS POINT THAT APPEARS TO BE A LOW PROBABILITY OF OCCURRENCE AND WOULD STILL BE VFR. /OUTLOOK FOR KMSP/ FRIDAY...VFR. SOUTH WIND 5 TO 15 KT. FRIDAY NIGHT...MVFR CEILINGS EXPECTED LATE. IFR CEILINGS AND MVFR VISIBILITIES POSSIBLE WITH A CHANCE OF RAIN. SOUTHEAST WIND 10 TO 20 KT. SATURDAY...MVFR CEILINGS AND VISIBILITIES EXPECTED WITH RAIN... IFR POSSIBLE. SOUTHEAST WIND 15 TO 20 KT. SATURDAY NIGHT...MVFR CEILINGS AND VISIBILITIES EXPECTED WITH RAIN... IFR POSSIBLE. SOUTH WIND 10 TO 20 KT BECOMING SOUTHWEST. SUNDAY...MVFR CEILINGS AND VISIBILITIES POSSIBLE WITH A CHANCE OF RAIN/SNOW... IFR POSSIBLE EARLY. WEST WIND 10 TO 20 KT BECOMING NORTHWEST 15 TO 25 KT. SUNDAY NIGHT...MVFR CEILINGS POSSIBLE EARLY. NORTHWEST WIND 10 TO 20 KT. MONDAY...VFR. NORTHWEST WIND 5 TO 15 KT. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...TRH LONG TERM...RAH AVIATION...LRS
AREA FORECAST DISCUSSION
NWS DULUTH MN
1123 PM CST WED NOV 13 2013 .UPDATE... ISSUED AT 1124 PM CST WED NOV 13 2013 UPDATE FOR THE AVIATION DISCUSSION BELOW... UPDATE ISSUED AT 836 PM CST WED NOV 13 2013 PARTS OF THE FORECAST WERE UPDATED THROUGH THURSDAY. THE FOCUS IS ON THE CLOUD COVER AND PCPN CHANCES/TYPE. THERE ARE SCT/BKN HIGH CLOUDS MOVING ACROSS THE NORTHLAND THIS EVENING AS AN ILL DEFINED TROUGH MOVES THROUGH THE REGION. THESE CLOUDS SHOULD CONTINUE TO SPREAD ACROSS THE FORECAST AREA THROUGH TONIGHT. THE CLOUD COVER AND LIGHT SW TO W WINDS SHOULD HELP BOLSTER TEMPERATURES JUST A TAD...SO I RAISED THE LOW TEMPERATURE FORECAST JUST A BIT IN SPOTS. I HAVE SOME CONCERNS ABOUT THE DEVELOPMENT OF LOW CLOUDS AND/OR FOG LATE TONIGHT AND IN THE MORNING BEFORE THE BOUNDARY LAYER MIXES OUT LATER IN THE MORNING. MODEL SOUNDINGS ARE SUGGESTING A SATURATED BOUNDARY LAYER WILL DEVELOP LATE TONIGHT. HOWEVER...THERE IS A RELATIVELY DEEP DRY LAYER ABOVE THE BOUNDARY LAYER...AND THE LIGHT SW TO W FLOW AND ITS MIXING MAY BE ENOUGH TO PREVENT LOW CLOUDS AND/OR FOG FROM FORMING. THEREFORE...I REFRAINED FROM DRAMATICALLY INCREASING CLOUD COVER TONIGHT AND TOMORROW MORNING AND DID NOT ADD FOG INTO THE FORECAST...BUT THIS IS SOMETHING THE NIGHT SHIFT WILL NEED TO REEVALUATE. THERE SHOULD BE INCREASING CLOUDS FROM THE NORTH LATE TONIGHT. THERE IS ALREADY A LARGE AREA OF LOW CLOUDS ACROSS MUCH SOUTH CENTRAL CANADA...SO I EXPECT THE CLOUDS TO BEGIN TO ROLL INTO THE BORDERLAND LATE TONIGHT. THERE WILL BE INCREASING PCPN CHANCES FROM THE NORTH TOMORROW MORNING. I SLIGHTLY ALTERED THE PCPN TYPE FORECAST SO THAT IT BEGINS AS SNOW THROUGH THE MORNING...AND THEN A MIX OF RAIN AND SNOW IN THE AFTERNOON. THE PREVIOUS FORECAST HAD RAIN IN THE LATE MORNING AND AFTERNOON...BUT SOUNDINGS AND SURFACE TEMPERATURES APPEAR TO SUPPORT AT LEAST SOME SNOW DURING THE AFTERNOON. THERE SHOULD BE LITTLE TO NO ACCUMULATION. SEVERAL MODELS ARE SUGGESTING THERE MAY BE A BAND OF PCPN ACROSS THE FAR SE FORECAST AREA LATE TONIGHT OR TOMORROW MORNING. MOST OF THE MODELS SUGGEST IT WILL BE MID TO LATE MORNING...BUT THE GFS AND HRRR SUGGEST IT MAY BE EARLIER. THIS PCPN WILL BE ASSOCIATED WITH THE CLOUDS AROUND 10 KFT CURRENTLY MOVING ACROSS THE FORECAST AREA. I SUSPECT IT WILL BEGIN AS VIRGA BECAUSE OF THE DRY LAYER UNDERNEATH THE CLOUD DECK. HOWEVER...WE WILL NEED TO MONITOR THIS EARLIER POTENTIAL FOR PCPN BECAUSE IF IT MANAGES TO REACH THE GROUND...THEN THERE COULD BE A SHORT WINDOW OF LIGHT FREEZING RAIN. IF IT HOLDS OFF TILL LATER IN THE MORNING...THE PCPN SHOULD BE RAIN. && .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 330 PM CST WED NOV 13 2013 A COUPLE OF WEAK SFC TROFS WERE WORKING THEIR WAY THROUGH THE CENTRAL AND EASTERN PORTIONS OF THE FA AT 19Z. MEANWHILE...A WARM FRONT WAS MOVING INTO THE WESTERN EDGE OF THE FA AND A COLD FRONT ENTERING THE RED RIVER VALLEY. THE MAIN IMPACTS WITH THESE FEATURES HAS BEEN WIND SHIFTS AND WARMER AIR BEHIND THE WARM FRONT AS SEEN IN SFC OBS WITH TEMPS AROUND 50F IN NW MN. TEMPS BEHIND THE COLD FRONT HAD REACHED THE LOWER 50S DUE TO COMPRESSIONAL WARMING. A GUSTY SW SFC WIND COVERED THE AREA AHEAD OF THE FRONTS ALONG WITH SOME CI CLOUDS. THE WARM FRONT WILL FALL APART AS IT MOVES THROUGH THE FA THIS EVENING. THE COLD FRONT WILL DISSIPATE AS IT REACHES THE WESTERN EDGE OF THE FA AND REFORM FURTHER S IN WEST CENTRAL MN. EVEN WITH ALL THIS FRONTAL ACTIVITY...NO PCPN IS EXPECTED TONIGHT DUE TO A LACK OF DEEP MOISTURE AND FORCING. CLOUDS HOWEVER WILL BE ON THE INCREASE AND KEEP MIN TEMPS IN THE UPPER 20S TO LOWER 30S. ON THURSDAY...ANOTHER COLD FRONT IS FORECAST TO DEVELOP IN SOUTHERN CANADA AND REACH THE INTERNATIONAL BORDER BY 18Z. A LONG WAVE TROF MOVES INTO MN AS WELL. THERE IS A BIT MORE MOISTURE AVAILABLE. THIS WILL AFFORD A SMALL POP OVER SOUTHERN PRICE COUNTY IN WI FOR LIGHT RAIN IN THE VCNTY OF A SFC TROF. LOW CHANCE POPS IN THE VCNTY OF THE COLD FRONT. PTYPE WILL START AS ALL SNOW NEAR THE CANADIAN BORDER WITH A MIX OF RAIN AND SNOW BY MID MORNING THURSDAY BEFORE TRANSITIONING TO ALL RAIN BY AFTERNOON. AMOUNTS WILL BE LIGHT. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 330 PM CST WED NOV 13 2013 A WARM SOUTHERLY FLOW SETS UP ACROSS THE UPPER MIDWEST FRIDAY/SATURDAY AS A LONG WAVE TROUGH DEEPENS OVER THE ROCKIES. THE NORTHLAND BECOMES SITUATED INT HE WARM SLOT AHEAD OF THE TOUGH SATURDAY. THERE IS GOOD MODEL AGREEMENT THAT A SURGE OF MOISTURE LIFTS INTO THE GREAT LAKES REGION FRIDAY NIGHT/SATURDAY WITH PWATS RAPIDLY INCREASING INTO THE 0.6-0.8" RANGE. HAVE KEPT LIKELY POPS FOR RAIN OVER THE EASTERN ZONES...WHILE THERE REMAINS SOME UNCERTAINTY IN THE WESTWARD EXTENT OF THE PRECIP SAT. BASED ON NAM BUFR SOUNDINGS AND MID-LVL TEMP PROFILES HAVE PTYPE REMAINING ALL RAIN FRIDAY NIGHT THROUGH SATURDAY. THERE IS A VERY MINIMAL THREAT FOR -FZDZ IF THE SFC TEMPS FALL BELOW FREEZING...BUT CLOUD TOP TEMPS REMAIN WELL ABOVE FREEZING AND LIMIT ANY ICE GROWTH. FOCUS TURNS TO CYCLOGENESIS OVER THE CENTRAL PLAINS SATURDAY NIGHT. THE 12Z RUNS OF THE GFS/ECM CONTINUE TO HAVE RUN TO RUN VARIABILITY IN THE STORM TRACK AND TIMING. HOWEVER...THERE IS AGREEMENT THAT THE H85 TROUGH DEEPENS INTO A CLOSED LOW AS IT LIFTS OVER MINNESOTA/WISCONSIN DURING THE SATURDAY NIGHT/SUNDAY TIME FRAME. AS EXPECTED...THE GFS REMAINS THE FASTER OF THE TWO SOLUTIONS BY A GOOD 12HR. THE GFS SUGGESTS THE H85 LOW CENTER TRACKS ACROSS THE MN ARROWHEAD EARLY SUNDAY MORNING...WHILE THE ECM BRINGS THE H85 LOW OVER NRN WISCONSIN SUNDAY AFTERNOON. THE DIFFERENCE IN STORM TRACK WILL DETERMINE THE RAIN/SNOW TRANSITION ZONE AND SNOWFALL AMOUNTS ASSOCIATED WITH THIS SYSTEM. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1124 PM CST WED NOV 13 2013 LIGHT SW TO W WINDS ARE EXPECTED ACROSS NE MINNESOTA AND NW WISCONSIN THROUGH THURSDAY. THE VFR CONDITIONS ACROSS THE REGION SHOULD CONTINUE THROUGH THE NIGHT...BUT THERE IS A VERY LOW POSSIBILITY OF IFR/MFVR CIGS DEVELOPING LATE TONIGHT. OTHERWISE...MVFR CIGS AND/OR VFR CIGS IN THE 3 TO 5 KFT RANGE WILL BEGIN TO DEVELOP THURSDAY MORNING. THERE MAY BE SOME -SN AND -RA ACROSS NORTHERN MINNESOTA...INCLUDING KINL AND KHIB...LATE THURSDAY MORNING AND THROUGH THURSDAY EVENING. && .PRELIMINARY POINT TEMPS/POPS... DLH 31 42 30 41 / 0 10 10 10 INL 27 35 26 38 / 10 30 30 10 BRD 30 44 29 44 / 0 10 10 20 HYR 28 43 29 44 / 10 10 10 10 ASX 32 43 31 44 / 0 10 10 10 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...SMALL CRAFT ADVISORY UNTIL 4 AM CST THURSDAY FOR LSZ140>142. && $$ UPDATE...GROCHOCINSKI SHORT TERM...GSF LONG TERM...GRANING AVIATION...GROCHOCINSKI
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
351 PM CST Thu Nov 14 2013 .SHORT TERM: (Through Late Tonight) Issued at 348 PM CST Thu Nov 14 2013 A dry air mass with low dew points will promote efficient cooling tonight, however WAA and mid/high clouds will temper the drop-off and keep overnight lows in the mid 30s. Kanofsky .LONG TERM: (Friday through Next Thursday) Issued at 348 PM CST Thu Nov 14 2013 A weak disturbance was located over central NM around 21z per water vapor imagery and recent RAP 1.5 PVU analyses. This feature will quickly swing through TX tonight before reaching AR and MS tomorrow. Although the air mass over MO/IL remains fairly dry, a few sprinkles or light rain showers are possible over the eastern Ozarks on Fri morning before this vort max lifts away from the area. Look for a continued warming trend through the weekend due to persistent southwest surface flow along with warming temperatures aloft. Highs will probably reach the mid to upper 70s on Sun despite substantial cloud cover and periods of precipitation. High temperatures will fall back into the 30s and 40s early next week after a strong cold front moves across the region on Sunday afternoon and evening. Wind speeds will increase on Fri night as the pressure gradient tightens between the surface high over the southeast US and the developing low pressure system over the plains. Expect breezy conditions through Sun with the highest wind speeds and gusts on Sat. Two low pressure systems are expected to affect our area this weekend. The first vort max was located near the WA coast around 18z this afternoon and is forecast to reach KS by Sat. The LLJ induced by this feature will interact with a lifting warm front to produce an area of rain on late Fri night and Sat morning. PW values are forecast to rise to around 1.2" by Sat, which is around +2 SD for November, so plenty of moisture will be available. There will probably be a break in the rain sometime on Sat aftn between systems. A stronger vort max is forecast to cross the Rockies and induce surface cyclogenesis along the pre-existing baroclinic zone over OK/KS on Sat night. Instability and lift ahead of this system should support an area of rain showers with embedded thunderstorms. The attendant cold front then moves through the CWA on Sun aftn/eve as the system lifts towards the Great Lakes and begins to occlude. With substantial shear in place along with at least some instability, there is a potential for severe thunderstorms on Sun ahead of the advancing cold front. Although there are some timing differences between models, most of the latest model runs bring the cold front through the LSX CWA before 00z Mon. Such timing would limit the severe weather threat across our area to the far eastern CWA at most. If future model runs support a slower fropa, then there may be more of a concern for severe thunderstorms. Kanofsky && .AVIATION: (For the 18z TAFs through 18z Friday Afternoon) Issued at 1132 AM CST Thu Nov 14 2013 Primary weather concern this afternoon will be south to southwest winds that will occasionally gust into the 20-25 kt range...mainly over the northwest half of the CWA. These winds will diminish heading into the early evening hours, and ramping up of low level jet may cause some LLWS concerns after 03z. Progged low level winds from NAM are just a bit below LLWS criteria but it will be close, and evening shift will need to keep an eye on this. While any cloudiness through this evening will be limited to cirrus, lower level moisture return on Friday morning should mean a gradual lowering of cigs but attm it appears cloud bases will remain aoa 5kft. Specifics for KSTL: Winds of 200-210 degrees will occasionally gust to around 20 kts this afternoon, with surface winds backing a bit and rapidly diminishing into the 8-10kt range by early this evening. As mentioned in primary AFD will need to keep an eye on LLWS potential later this evening and overnight, as winds at the 1500-2000 agl are progged to increase into the 35-40kt range. Cloudiness through 06z will be aoa 10kft. Truett && .CLIMATE: Issued at 348 PM CST Thu Nov 14 2013 Record highs for Sunday, November 17th STL 78 1958 COU 78 1958 UIN 78 1952 && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
338 PM CST Thu Nov 14 2013 .SHORT TERM: (Through Late Tonight) Issued at 336 PM CST Thu Nov 14 2013 A dry air mass with low dew points will promote efficient cooling tonight, however WAA and mid/high clouds will temper the drop-off and keep overnight lows in the mid 30s. Kanofsky .LONG TERM: (Friday through Next Thursday) Issued at 336 PM CST Thu Nov 14 2013 A weak disturbance was located over central NM around 21z per water vapor imagery and recent RAP 1.5 PVU analyses. This feature will quickly swing through TX tonight before reaching AR and MS tomorrow. Although the air mass over MO/IL remains fairly dry, a few sprinkles or light rain showers are possible over the eastern Ozarks on Fri morning before this vort max lifts away from the area. Look for a continued warming trend through the weekend due to persistent southwest surface flow along with warming temperatures aloft. Highs will probably reach the mid to upper 70s on Sun despite substantial cloud cover and periods of precipitation. High temperatures will fall back into the 30s and 40s early next week after a strong cold front moves across the region on Sunday afternoon and evening. Wind speeds will increase on Fri night as the pressure gradient tightens between the surface high over the southeast US and the developing low pressure system over the plains. Expect breezy conditions through Sun with the highest wind speeds and gusts on Sat. Two low pressure systems are expected to affect our area this weekend. The first vort max was located near the WA coast around 18z this afternoon and is forecast to reach KS by Sat. The LLJ induced by this feature will interact with a lifting warm front to produce an area of rain on late Fri night and Sat morning. PW values are forecast to rise to around 1.2" by Sat, which is around +2 SD for November, so plenty of moisture will be available. There will probably be a break in the rain sometime on Sat aftn between systems. A stronger vort max is forecast to cross the Rockies and induce surface cyclogenesis along the pre-existing baroclinic zone over OK/KS on Sat night. Instability and lift ahead of this system should support an area of rain showers with embedded thunderstorms. The attendant cold front then moves through the CWA on Sun aftn/eve as the system lifts towards the Great Lakes and begins to occlude. With substantial shear in place along with at least some instability, there is a potential for severe thunderstorms on Sun ahead of the advancing cold front. Although there are some timing differences between models, most of the latest model runs bring the cold front through the LSX CWA before 00z Mon. Such timing would limit the severe weather threat across our area to the far eastern CWA at most. If future model runs support a slower fropa, then there may be more of a concern for severe thunderstorms. Kanofsky && .AVIATION: (For the 18z TAFs through 18z Friday Afternoon) Issued at 1132 AM CST Thu Nov 14 2013 Primary weather concern this afternoon will be south to southwest winds that will occasionally gust into the 20-25 kt range...mainly over the northwest half of the CWA. These winds will diminish heading into the early evening hours, and ramping up of low level jet may cause some LLWS concerns after 03z. Progged low level winds from NAM are just a bit below LLWS criteria but it will be close, and evening shift will need to keep an eye on this. While any cloudiness through this evening will be limited to cirrus, lower level moisture return on Friday morning should mean a gradual lowering of cigs but attm it appears cloud bases will remain aoa 5kft. Specifics for KSTL: Winds of 200-210 degrees will occasionally gust to around 20 kts this afternoon, with surface winds backing a bit and rapidly diminishing into the 8-10kt range by early this evening. As mentioned in primary AFD will need to keep an eye on LLWS potential later this evening and overnight, as winds at the 1500-2000 agl are progged to increase into the 35-40kt range. Cloudiness through 06z will be aoa 10kft. Truett && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
337 AM CST THU NOV 14 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 337 AM CST THU NOV 14 2013 MODELS IN FAIR AGREEMENT IN THE NEAR TERM. UPPER TROUGH MOVING EAST ACROSS THE FORECAST AREA TODAY WITH HIGH BASED SHOWERS OVER NORTHWEST NEBRASKA SLIDING EAST. CHADRON HAS REPORTED LIGHT PRECIPITATION FOR A WHILE BUT PINE RIDGE JUST STARTED. WILL RETAIN SPRINKLES ACROSS NORTHERN ZONES THROUGH MID MORNING WITH EASTERLY MOVEMENT AROUND 20KTS. TEMPERATURES HOLDING UP WITH CLOUD COVER THIS MORNING. NORTHERLY WINDS STARTING TO INCREASE OVER THE NORTHERN PANHANDLE AND THIS WILL TRANSLATE EAST THROUGH THE DAY. HIGHS SOME TEN DEGREES COOLER TODAY. CLEARING SKIES TONIGHT AND LIGHT SOUTHERLY FLOW LOW TEMPERATURES FALLING TO AROUND 30. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 337 AM CST THU NOV 14 2013 MODELS CONTINUE TO SHOW TROUGH DIGGING ACROSS THE WEST FRIDAY AND QUICKLY TRANSITIONING EAST TO THE GREAT LAKES BY MONDAY. AT THE SFC A COUPLE OF LOW PRESSURE SYSTEMS WILL MOVE ACROSS THE PLAINS. THE FIRST LOW IS EXPECT TO LIFT NE ACROSS THE CENTRAL PLAINS SATURDAY. TRACK STILL UNCERTAIN AS MODELS CONTINUE TO WOBBLE AS IT LIFTS ACROSS PORTIONS OF KS/NEB. MODEL CONSENSUS IS TO LIFT IT QUICKLY ACROSS NW KS/S CENTRAL THEN E NEBRASKA. RAIN/THUNDER LOOKS GOOD TO THE EAST OF THE CWA...HOWEVER LIMITED MOISTURE AND WARM BL LOOKS TO KEEP THE OUR PART OF NEB DRY. MODELS HAVE EVEN CUT BACK ON RH PERCENTAGES ALOFT WITH MAV GUIDANCE EVEN SHOWING SCT SKIES. THUS THINK THERE COULD BE SOME PEAKS OF SUN AND TRENDED WITH GUIDANCE AND RAISED TEMPS. SATURDAY NIGHT/SUNDAY A COLD FRONT WILL PUSH ACROSS THE AREA. TEMPS NOTICEABLY COOLER SUNDAY...ESPECIALLY ACROSS THE NW AS THE COLD AIR ARRIVES EARLY WITH HIGHS LIKELY IN THE MORNING. PRECIP CHANCES SPREAD TO THE SOUTH AS THE COLD AIR CONTINUES TO FILL IN BEHIND THE FRONT. SOUNDING PROFILES COOL QUICKLY WITH RAIN TO CHANCE TO SNOW DURING THE DAY/EVENING FROM NW TO SE. THE HOLD OUT FOR CHANGE OVER TO SNOW WILL BE SURF TEMPS AS THEY WARM INTO THE 40S AHEAD OF THE FRONT AND WILL TAKE SOME TIME TO COOL DURING THE DAYLIGHT HOURS. GROWING CONCERN ABOUT PRECIP CHANCES...AS MODELS ARE FASTER WITH THE UPPER TROUGH AND THE JET SUPPORT IS QUICKER TO PUSH EAST. MODELS IN AGREEMENT IN REDUCING QPF AMOUNTS...AND MOS GUIDANCE HAS REDUCED POPS. DO EXPECT AT LEAST CLOUDS AND SOME LIGHT PRECIP...ALTHOUGH NOT LOOKING AS IMPRESSIVE AS COUPLE OF DAYS AGO...WILL CONTINUE TO MONITOR. THE BIGGEST CHANGE FROM PREVIOUS RUNS OCCURS NEXT WEEK. THE FASTER PROGRESSION OF THE SYSTEM ALLOWS WARMER AIR TO RETURN QUICKLY TO THE HIGH PLAINS. A COUPLE DAYS AGO 850 MB TEMPS BOTTOMED OUT IN THE -10 TO -15 DEGREE C RANGE MONDAY MORNING WITH A SLOW REBOUND...HOWEVER NOW THEY BARELY FALL BELOW ZERO DEGREES C. GUIDANCE FOLLOWS SUIT WITH MONDAY AND TUESDAY SOME 5 TO 15 DEGREES WARMER FROM THE 12Z RUN FOR HIGHS. CLEARING SKIES AND HIGH PRESSURE OVERHEAD SUNDAY NIGHT SHOULD STILL ALLOW FOR LOWS IN THE TEENS...HOWEVER TEMPS ARE ABLE TO REBOUND QUICKLY...WELL INTO THE 40S AND EVEN 50S POSSIBLE AS EARLY AS MONDAY. THE 00Z EC HAS ARRIVED WITH THE WARMEST CONDITIONS WITH GUIDANCE SUGGESTION HIGHS COULD NEAR 60 BY TUESDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1130 PM CST WED NOV 13 2013 THE LATEST RAP AND NAM MODEL SOLNS SUGGEST AN AREA OF MVFR CIGS MAY DEVELOP ALONG AND WEST OF HIGHWAY 61 FROM KOGA NORTH BETWEEN 06Z AND 12Z. IT ALSO LOOKS LIKE SCATTERED LIGHT SHOWERS WILL MOVE THROUGH NRN NEB OVERNIGHT...PERHAPS AS FAR EAST AS KVTN. SOME SOLNS LIKE THE GFS AND HRRR MODELS CARRY THE SHOWERS THROUGH KONL. GIVEN THE DRY AIR AT THE LOWER LEVELS...THIS MIGHT BE A STRETCH BUT SPRINKLES ARE POSSIBLE IN THAT AREA. OTHERWISE VFR IS EXPECTED ALL AREAS FROM 12Z ON THROUGH 06Z THURSDAY EVENING. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...POWER LONG TERM...MASEK AVIATION...CDC
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1130 PM CST WED NOV 13 2013 .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 322 PM CST WED NOV 13 2013 A WEAK UPPER LEVEL DISTURBANCE WILL TRACK SOUTHEAST FROM NORTHWEST WYOMING INTO WESTERN NEBRASKA OVERNIGHT. WILL CONTINUE THE SLIGHT CHANCE FOR SHOWERS AS THIS DISTURBANCE MOVES ACROSS...BUT DRY AIR IN THE MID LEVELS OF THE ATMOSPHERE WILL KEEP ANY PRECIPITATION ISOLATED THAT MANAGES TO REACH THE GROUND. OTHERWISE A WEAK COLD FRONT WILL PUSH SOUTHEAST...WITH TEMPERATURES ACTUALLY RISING AFTER THE FRONTAL PASSAGE AS WARMER AIR ALOFT IS MIXED TO THE SURFACE. LOWS ACROSS NORTHERN NEBRASKA WILL BE VERY MILD...NEAR 40 DEGREES. A LITTLE COOLER FARTHER SOUTH AHEAD OF THE FRONT...WHERE CALM WINDS WILL ALLOW FOR TEMPERATURES TO DROP INTO THE LOWER AND MID 30S AROUND MIDNIGHT...BUT THEN RISE TO UPPER 30S AFTER THE FRONT PASSES AND WIND INCREASES. ANOTHER MILD DAY EXPECTED THURSDAY...BUT NOT QUITE AS WARM AS TODAY. TEMPERATURES ALOFT WILL COOL SOME...AND NOT MUCH MIXING EXPECTED WITH LIGHT WINDS. HIGHS IN THE LOWER TO MID 50S LOOK GOOD FOR MOST LOCALS. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 322 PM CST WED NOV 13 2013 THE GFS40..GEMNH...NAM12 AND THE 00Z ECMWF SHOW GOOD AGREEMENT WITH THE CYCLOGENESIS OVER COLORADO FRIDAY AND FRIDAY NIGHT AND WITH THE TRACK OF THE SYSTEM. A CROSS-SECTION FROM ONEILL TO HOLDREGE SHOWS SOME ISENTROPIC UPGLIDE AHEAD OF THE SYSTEM IN THE 300-310K LAYER. THE LIFTED PARCELS ARE NOWHERE NEAR SATURATED...SO ACTUAL PRECIPITATION AMOUNTS WILL BE LIMITED. IN FACT...FORECAST SOUNDINGS IN THE AREA INDICATE A SHALLOW LAYER OF SUPER-COOLED SATURATED AIR AND WEAK LIFT THAT IS MORE INDICATIVE OF DRIZZLE. WITH SURFACE TEMPERATURES OF 30F...ANY THAT DOES FALL WILL PROBABLY FREEZE ON SURFACES. THERE ARE STILL SIGNIFICANT DIFFERENCES AMONG THE MODELS WITH THE SYSTEM EARLY NEXT WEEK...SO THE UNCERTAINTY REMAINS HIGH. THERE IS A TIMING DIFFERENCE BETWEEN THE GFS40 AND THE GEMNH OF ABOUT 6 HOURS. THE 12Z ECMWF IS A LITTLE SLOWER YET. OTHERWISE...THEY ARE SHOWING A SIMILAR PATTERN WITH AN OPEN UPPER WAVE CROSSING THE CENTRAL AND NORTHERN PLAINS AT LEAST UNTIL THE SYSTEM MOVES INTO THE UPPER MISSISSIPPI VALLEY. AN ARCTIC FRONT IS EXPECTED TO CROSS NEBRASKA SUNDAY AND SUNDAY NIGHT. LOOKING AT A CROSS SECTION FROM ABOUT GILLETTE WYOMING TO NEAR EMPORIA KANSAS AND FROM VALENTINE TO MCCOOK...THE COMBINATION OF SYSTEM-RELATIVE ISENTROPIC LIFT IN THE 290-300K LAYER AND INSTABILITY INDICATED BY FOLDED THETA-E WILL GENERATE STRONG UPWARD MOTION. MODERATE MOISTURE IS AVAILABLE WITH SPECIFIC HUMIDITY IN THAT LAYER OF 1-3G/KG. HOWEVER...THE SYSTEM IS A QUICK HIT AND...BECAUSE IT WILL BE ONLY ABOUT EIGHT HOURS DURATION...THE PRECIPITATION AMOUNTS WILL BE LIMITED. IN FACT...THE QPF OF 0.07-0.12 INDICATED BY THE GFS SEEMS REASONABLE. THERE IS ENOUGH LIFT AND MOISTURE IN THE DENDRITIC LAYER THAT SNOW PRODUCTION SHOULD BE EFFICIENT. A FORECAST SOUNDING FOR NORTH PLATTE...WHICH IS ABOUT THE MIDDLE OF THE MAXIMUM UPWARD MOTION...SHOWS A FAIRLY WARM LAYER BELOW 725MB WITH THE WET BULB ZERO NEAR 820MB. THAT SHOULD RESULT IN FAIRLY RAPID COOLING AND LIGHT RAIN CHANGING OVER TO SNOW. ACCUMULATIONS WILL NOT BE HEAVY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1130 PM CST WED NOV 13 2013 THE LATEST RAP AND NAM MODEL SOLNS SUGGEST AN AREA OF MVFR CIGS MAY DEVELOP ALONG AND WEST OF HIGHWAY 61 FROM KOGA NORTH BETWEEN 06Z AND 12Z. IT ALSO LOOKS LIKE SCATTERED LIGHT SHOWERS WILL MOVE THROUGH NRN NEB OVERNIGHT...PERHAPS AS FAR EAST AS KVTN. SOME SOLNS LIKE THE GFS AND HRRR MODELS CARRY THE SHOWERS THROUGH KONL. GIVEN THE DRY AIR AT THE LOWER LEVELS...THIS MIGHT BE A STRETCH BUT SPRINKLES ARE POSSIBLE IN THAT AREA. OTHERWISE VFR IS EXPECTED ALL AREAS FROM 12Z ON THROUGH 06Z THURSDAY EVENING. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...TAYLOR LONG TERM...SPRINGER AVIATION...CDC
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1239 AM EST THU NOV 14 2013 .SYNOPSIS... A RIDGE OF HIGH PRESSURE WILL SLIDE OFF TO THE SOUTH ALLOWING A WEST TO SOUTHWEST FLOW TO DEVELOP AND GRADUALLY BRING MILDER AIR BACK INTO THE REGION TONIGHT THROUGH THIS WEEKEND. IT WILL BE MAINLY DRY WITH THE NEXT CHANCE OF SIGNIFICANT PRECIPITATION EARLY NEXT WEEK IN THE FORM OF RAIN SHOWERS. && .NEAR TERM /UNTIL 7 AM THIS MORNING/... AS OF 946 PM EST WEDNESDAY...LOW-LEVEL WARM AIR ADVECTION REGIME UNDERWAY ACROSS THE NORTH COUNTRY WITH INCREASING SOUTH/SOUTHWEST SFC WINDS. INITIAL AREA OF OVERCAST SKIES EARLIER THIS EVENING HAS SINCE SHIFTED EASTWARD WITH INFRARED SATELLITE AND OBSERVATIONS INDICATING THAT UPSTREAM CLOUDINESS IS MAINLY AT MID-LEVELS. THOUGH CLOUDINESS IS BEGINNING TO THIN OUT...STILL BELIEVE THAT LOW TEMPS HAVE ALREADY BEEN REACHED IN MANY AREAS AS STRENGTHENING WIND FIELDS WILL HELP KEEP BOUNDARY LAYER WELL MIXED AND WITH LOW LEVELS WARMING. TEMPS WILL THEN CONTINUE TO FOLLOW A NON-DIURNAL TREND WITH TEMPS HOVERING OR SLIGHTLY RISING FROM CURRENT READINGS THROUGH THE REST OF THE EVENING. I`VE REMOVED THE SLIGHT CHANCE/CHANCE POPS ACROSS THE ADIRONDACKS AND SAINT LAWRENCE VALLEY. SOME QUESTION AS TO HOW MUCH LAKE EFFECT CAN TAKE PLACE AS RECENT HRRR RUNS HAVE BECOME LESS BULLISH ON ITS POTENTIAL. THERE`S FAVORABLE TRAJECTORIES FOR LAKE MOISTURE ADVECTION AND I COULD SEE SOME ENHANCEMENT IN CLOUDINESS THERE. HOWEVER WITH MODEL SOUNDINGS SHOWING AN UNSATURATED ICE NUCLEI LAYER...IF ANYTHING WERE TO FALL OUT OF ANY LAKE EFFECT CLOUDS IT MAY NOT AMOUNT TO MUCH MORE THAN LIGHT DRIZZLE. SO I`VE OPTED TO SIDE WITH THE HRRR AND REMOVE MENTION OF ANY SNOW SHOWERS FOR THIS EVENING. && .SHORT TERM /7 AM THIS MORNING THROUGH FRIDAY NIGHT/... AS OF 330 PM EST WEDNESDAY...DRY AND FAIR WEATHER WILL CONTINUE FROM THURSDAY THROUGH FRIDAY NIGHT AS SURFACE HIGH REMAINS THE MAIN WEATHER FEATURE ACROSS THE NORTH COUNTRY. TEMPERATURES WILL WARM INTO THE UPPER 30S TO MID 40S TOMORROW WITH SOUTHERLY FLOW IN PLACE ACROSS THE AREA USHERING IN SOME MILDER AIR. TEMPS THURSDAY NIGHT WILL BE EVEN WARMER THAN TONIGHT WITH WARM AIR ADVECTION CONTINUING ON SOUTHERLY FLOW. THE WARMING TREND WILL CONTINUE FOR FRIDAY AND FRIDAY NIGHT WITH EACH PERIOD A FEW DEGREES WARMER THAN THE PREVIOUS DAYS MAX AND MIN TEMPS. THERE WILL BE SOME CLOUDS AROUND DUE TO WEAK SHORTWAVES CROSSING THE REGION DURING THE SHORT TERM. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... AS OF 300 PM EST WEDNESDAY...FOR THE EXTENDED PERIOD...MUCH OF THE UPCOMING WEEKEND OVER THE ENTIRE CWA WILL HAVE ABV NORMAL CONDITIONS...AS HIGH PRESSURE SITS OFFSHORE TO OUR EAST AND LOW PRESSURE W/ ASSOCIATED STRONG CD FRONT RESIDES OVER THE GREAT LKS/MIDWEST REGION. THIS WILL KEEP THE REGION UNDER STRONG WAA ON SSW FLOW. 925MB TEMPS INCR FROM 0C TO +4C ON SATURDAY TO +8C TO +10C ON SUNDAY AS GRADIENT INCR AHEAD OF FRONT. AS A RESULT...LOOKING FOR SUNDAY TO BE THE WARMER OF THE 2-DAY PERIOD W/ HIGHS RAMPING UP FROM THE UPPER 40S/LOWS 50S TO THE 50S TO NEAR 60F IN SPOTS SUNDAY IN MANY SPOTS. TEMPS SUNDAY WILL BE CLD COVER DEPENDENT AS FRONT APPROACHES FOR N NY. MDLS IN FAIR CONSENSUS THAT FRONT WILL BE SLOW TO PUSH THRU REGION SUN NGT/MON DUE TO BLOCKING RIDGE OFFSHORE. AS A RESULT...CVLY WESTWARD WILL HAVE CHANCE FOR 50S FOR HIGHS BFR CD AIR BEHIND FRONT ARRIVES. STRONG JET DYNAMICS AHEAD OF FRONT FROM 925MB TO 700MB COULD BRING SFC WIND GUSTS NEAR 30-40MPH. W/ FRONT TAPPING INTO GULF MOISTURE...MDL QPF COULD BRING 0.50-1.00" RAINFALL AMTS. AS FRONT PASSES THRU AREA SUNDAY NGT/MONDAY...COLDER AIR ON INCR WNW FLOW BEHIND SYSTEM WILL BRING CHANGEOVER FROM -RW TO -SW AT HIR ELEV FIRST....THEN GOING INTO TUESDAY/WEDNESDAY WITH ENTIRE CWA SLIPPING FROM NEAR TO BLW NORMAL TEMPS...-SW FOR ALL AREAS WITH HIGHEST POPS ON HIR TRRN/NW FACING SLOPES. && .AVIATION /06Z THURSDAY THROUGH MONDAY/... THROUGH 06Z FRIDAY...AVIATION CHALLENGE WL BE LOW CIGS AT SLK THIS MORNING AND WINDS. SFC ANALYSIS SHOWS TIGHT PRES GRADIENT ACRS OUR TAF SITES CREATING BREEZY SOUTHWEST SFC WINDS. THIS WL CONT FOR MOST OF THE DAY WITH GUSTS BTWN 15 AND 25 KNOTS EXPECTED. IN ADDITION...THIS SOUTHWEST FLW WL HELP ADVECT LOW LEVEL LAKE ENHANCED MOISTURE IN SLK TODAY...WITH SOME LOWER CIGS ANTICIPATED. WL MENTION MVFR CIGS...BUT COULD SEE A BRIEF PERIOD OF IFR CIGS WITH AREAS OF BR/-DZ BTWN 10-16Z TODAY...BEFORE DRIER AIR DEVELOPS. OTHERWISE...SCATTERED TO BROKEN CIGS WL SLOWLY BECM MOSTLY CLR THIS AFTN...WITH SOUTHWEST WINDS. OUTLOOK 06Z FRIDAY THROUGH MONDAY... SFC HIGH PRES WL RESULT IN VFR CONDITIONS FOR FRIDAY WITH MAINLY LIGHT TRRN DRIVEN WINDS. SOME INCREASE IN CLOUDS ASSOCIATED WITH SEVERAL WEAK DISTURBANCES IN THE WINDS ALOFT WL BE POSSIBLE ON FRIDAY NIGHT INTO SATURDAY...BUT VFR CONDITIONS SHOULD PREVAIL. NEXT SYSTEM WL IMPACT REGION LATE SUNDAY INTO MONDAY WITH A PERIOD OF RAIN SHOWERS LIKELY AND MVFR CONDITIONS. IN ADDITION...VERY GUSTY SOUTHERLY WINDS BTWN 30 AND 40 KNOTS WL BE POSSIBLE AHEAD OF SFC COLD FRNT. THIS WL CREATE AREAS OF LLVL WS AND TURBULENCE...ESPECIALLY ACRS THE HIGHER TRRN AND OPEN VALLEY TERMINALS. A WIND SHIFT TO THE WEST WL OCCUR BY MONDAY NIGHT...WITH IMPROVING CONDITIONS. && .MARINE... WINDS SHIFT INTO THE SSW ACROSS LAKE CHAMPLAIN THIS EVENING...AND WILL INCREASE TO 15-25 KNOTS AFTER MIDNIGHT. THE HIGHEST WINDS AND WAVES - BUILDING TO 2-4 FEET - WILL BE ACROSS THE NORTHERN END OF THE BROAD LAKE TOWARD THE SOUTHERN PORTION OF GRAND ISLE. A LAKE WIND ADVISORY HAS BEEN POSTED FOR CONDITIONS EXPECTED AFTER MIDNIGHT. WINDS WILL SUBSIDE SLIGHTLY BY LATE MORNING THURSDAY...BUT LIKELY REMAIN S-SW 10-20 KNOTS THROUGH MOST OF THE DAYLIGHT HOURS. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...SISSON NEAR TERM...NEILES/LOCONTO SHORT TERM...NEILES LONG TERM...JN AVIATION...TABER MARINE...WFO BTV
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
949 PM EST FRI NOV 15 2013 .SYNOPSIS... A WARM FRONT AND COASTAL TROUGH WILL BRING SHOWERS TONIGHT. ABOVE NORMAL TEMPERATURES ARE EXPECTED THROUGH THE WEEKEND WITH THE RISK FOR SHOWERS INCREASING AGAIN LATE SUNDAY INTO MONDAY AS A COLD FRONT APPROACHES FROM THE WEST. THE FRONT WILL CROSS THE AREA MONDAY AFTERNOON...FOLLOWED BY DRIER AND COOLER CONDITIONS THROUGH MUCH OF NEXT WEEK. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... AS OF 930 PM FRIDAY...I`VE GOT TO SAY...THIS FORECAST ISN`T WORKING OUT LIKE I HAD HOPED. THE 00Z CHARLESTON SOUNDING SHOWS PRECIPITABLE WATER HAS RISEN TO NEARLY 1.3 INCHES...BUT ALSO SHOWS SEVERAL 3000-5000 FT THICK DRY LAYERS LOCATED RIGHT IN THE ZONE I WOULD EXPECT THE BEST ISENTROPIC LIFT TO BE OCCURRING. THE 00Z NAM INITIALIZED QUITE WELL VERSUS THE CHARLESTON THERMAL/MOISTURE PROFILE AND HAS REALLY TONED DOWN ITS RAINFALL POTENTIAL THROUGH 12Z. THE 18Z GFS WAS FAR TOO WET AND SHOWS TOO MUCH MOISTURE THROUGHOUT THE 700-400 MB LAYER VERSUS THE CHARLESTON SOUNDING. THE LATEST HRRR ALSO IS NOT CAPTURING TRENDS WELL AND IS BEING IGNORED. CHANGES WITH THIS UPDATE INCLUDE CUTTING POPS BACK TO 40-50 PERCENT FOR THE REMAINDER OF THE NIGHT AND SLASHING QPF FORECASTS TO AROUND 0.05 INCHES. WHILE THE LOCATION AND DEGREE OF ISENTROPIC LIFT HAS PROBABLY BEEN WELL-FORECAST BY THE MODELS ALL ALONG...DRY LIFT DOESN`T YIELD RAINFALL. BREAKS HAVE EVEN OPENED IN THE OVERCAST DECK NEAR GEORGETOWN...MYRTLE BEACH AND CONWAY IN THE PAST HOUR. :( AN INVERTED TROUGH JUST OFFSHORE IS THE SURFACE FEATURE WE ARE WATCHING THIS EVENING. IT EXTENDS NORTH FROM A WEAK LOW JUST EAST OF JACKSONVILLE FL. IN THE UPPER LEVELS A SHORTWAVE TROUGH ACROSS THE SOUTHERN AND CENTRAL APPALACHIANS WILL SWEEP OFFSHORE AFTER MIDNIGHT. A PUSH OF WESTERLY MID-LEVEL WINDS BEHIND THIS FEATURE SHOULD HELP NUDGE THE SURFACE TROUGH FARTHER OFFSHORE AS WELL. OUR LOW LEVEL WINDS WILL BECOME QUITE LIGHT AS THE TROUGH SHIFTS OFFSHORE LATE...WITH LITTLE OPPORTUNITY FOR THE CHILLIER AIR IN THE MOUNTAINS TO ADVECT DOWN TOWARD THE COAST. OVERNIGHT LOW TEMPERATURES ARE STILL EXPECTED TO RANGE FROM THE MID 50S ON THE COAST TO AROUND 50 ON THE INTERSTATE 95 CORRIDOR. THIS IS ON THE HIGH END OF MOS GUIDANCE BUT SEEMS REASONABLE GIVEN PREDOMINANTLY CLOUDY SKIES AND NO SUBSTANTIAL COLD ADVECTION EXPECTED THROUGH DAYBREAK. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/... AS OF 3 PM FRIDAY...A COASTAL TROUGH WILL BE PRESENT OFFSHORE ON SAT. THIS TROUGH WILL LIFT N AND THEN DISSIPATE THROUGH SAT NIGHT. EXPECT ANY LIGHT PRECIPITATION TO BE ENDING DURING SAT. INLAND AREAS SHOULD SEE AN END TO THE SHOWERS IN THE MORNING. SHOWERS MAY LINGER ALONG THE COAST INTO THE AFTERNOON...ESPECIALLY ACROSS THE CAPE FEAR COAST IN CLOSEST PROXIMITY TO THE TROUGH. MOISTURE PROFILES AND MODEL SOUNDINGS SHOW A GRADUAL DECREASE IN MOISTURE ON SAT. A PRONOUNCED NEAR SURFACE INVERSION LINGERS INTO SAT MORNING...BUT EVENTUALLY THE LOW-LEVEL MOISTURE DOES SCOUR OUT. THIS SHOULD ALLOW PARTIAL SUNSHINE TO DEVELOP SAT AFTERNOON WITH THE GREATEST CLOUD COVER LIKELY PERSISTING ACROSS THE CAPE FEAR REGION. A DEEPENING AND STRENGTHENING S TO SW FLOW WILL ENVELOP THE AREA SUN AND SUN NIGHT. ANOTHER PRONOUNCED LOW-LEVEL INVERSION IS EXPECTED TO DEVELOP SAT NIGHT AND THIS WILL LINGER INTO SUN MORNING. THIS INVERSION SHOULD ALLOW LOW STRATUS TO DEVELOP AND PERSIST INTO A GOOD PORTION OF SUN MORNING. AT THE SAME TIME...MID AND HIGH LEVEL MOISTURE WILL BE INCREASING AS PRECIPITABLE WATER VALUES CLIMB TO ABOUT AN INCH AND THREE- QUARTERS SUN EVE AND NIGHT. THUS...SUN LOOKS TO BE A RATHER CLOUDY DAY THROUGHOUT. THE COLUMN BECOMES SUFFICIENTLY MOIST IF NOT SATURATED THROUGH A DEEP LAYER SUN NIGHT AND WILL SHOW POPS INCREASING TO LIKELY OVERNIGHT. IT IS POSSIBLE SHOWERS DEVELOP EARLIER ON SUN...BUT MOST OF THE RAINFALL IS EXPECTED SUN NIGHT AND POSSIBLY INTO MON. AT THIS TIME WILL KEEP MENTION OF ONLY SHOWERS. HOWEVER...INCREASING CAPE VALUES WERE NOTED AND SO THERE IS A SMALL CHANCE FOR A RUMBLE OF THUNDER ALTHOUGH AT THIS TIME...FEEL THE RISK WILL BE CONFINED TO OFFSHORE AREAS WHERE BAROCLINICITY WILL BE HIGHEST. TEMPS WILL BE A DEG OR TWO ABOVE NORMAL BY DAY AS DEVELOPING WARM AIR ADVECTION IS MODERATED BY CONSIDERABLE CLOUD COVER...ESPECIALLY ON SUN. THIS WILL PUT HIGH TEMPS MAINLY IN THE LOWER TO PERHAPS MID 70S. LOW TEMPS WILL HOWEVER BE WELL ABOVE NORMAL...IN THE 50S SAT NIGHT AND IN THE 60S SUN NIGHT. THE NORMAL LOW TEMPS FOR MID NOV ARE IN THE MID 40S. && .LONG TERM /MONDAY THROUGH FRIDAY/... AS OF 3 PM FRIDAY...THE MID LEVEL PATTERN WILL CONSIST OF MAINLY A FLAT/ZONAL FLOW BEYOND MONDAY WHEN A WEAKENING TROUGH WILL USHER THROUGH ANOTHER FAST MOVING FRONT. I DID MAINTAIN THE LIKELY POPS WITH THIS FEATURE FOR ALL OF MONDAY...AT LEAST THROUGH 0000 UTC TUESDAY AS THERE REMAINS JUST ENOUGH DISAGREEMENT IN TIMING BETWEEN THE FASTER GFS SOLUTIONS AND SLOWER WPC PREFERRED ECMWF ENSEMBLE MEAN. WEEKEND SHIFTS SHOULD BE ABLE TO FINE TUNE TIMING. BEYOND THIS...HIGH PRESSURE BUILDS IN BUT THE COLD AIR ADVECTION IS DELAYED SOMEWHAT AS 850MB TEMPERATURES DON/T BOTTOM OUT UNTIL WEDNESDAY AFTERNOON. OVERALL TEMPERATURE TRENDS ARE SOMEWHAT BELOW NORMAL WITH WEDNESDAY AND THURSDAY THE COOLEST WARMING A BIT FRIDAY BASICALLY DUE TO AIR MASS MODIFICATION AND THE DEVELOPMENT OF A COASTAL TROUGH. TUESDAY TEMPERATURES ARE RIGHT AROUND NORMAL. && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/... AS OF 00Z...EXPECT VFR CONDITIONS THIS EVENING TO DETERIORATE TO MVFR/IFR OVERNIGHT ALONG WITH INCREASING PCPN CHANCES. CURRENT RADAR IMAGERY SHOWS SHRA OFFSHORE ASSOCIATED WITH A COASTAL TROUGH. HAVE INCLUDED VCSH FOR THE COASTAL TERMS TONIGHT WITH TEMPO PERIODS OF -SHRA POSSIBLE BEFORE MIDNIGHT. BETTER PCPN CHANCES WILL DEVELOP AFTER MIDNIGHT AS MOIST ISENTROPIC LIFT BRINGS RAIN TO OUR AREA... MORE CONCENTRATED ALONG THE COAST. CIGS ARE EXPECTED TO LOWER TO MVFR AFTER 06Z AS PCPN HELPS SATURATE THE LOWER LEVELS. IFR IS CERTAINLY POSSIBLE...PERHAPS MORE LIKELY AT KFLO/KLBT WHERE A MORE PRONOUNCED INVERSION SETS UP. THERE IS MORE UNCERTAINTY FOR THE COASTAL SITES...SO WILL KEEP PREVAILING MVFR ATTM. THE RAIN WILL COME TO AN END SATURDAY MORNING...THOUGH MVFR CIGS COULD LINGER INTO THE LATE MORNING BEFORE IMPROVING TO VFR. THE WINDS WILL BE LIGHT AND VARIABLE FOR MUCH OF THE PERIOD...BECOMING EAST AROUND 5 KTS DURING THE DAY. EXTENDED OUTLOOK...MVFR/IFR FOG POSSIBLE ON SUNDAY MORNING. EXPECT SHOWERS AND PERIODS OF MVFR/IFR EARLY MONDAY WITH A COLD FRONT. STRATUS POSSIBLE ALONG THE COAST ON WEDNESDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 930 PM FRIDAY...AN INVERTED SURFACE TROUGH EXTENDS SOUTH-TO- NORTH ACROSS THE CAROLINA COASTAL WATERS. ITS EXACT LOCATION IS TOUGH TO PIN DOWN WITH SPARSE OBSERVATIONS...BUT BASED ON WIND DIRECTIONS AT THE BEACHES AND AT THE FRYING PAN SHOALS BUOY PROBABLY LIES 10-15 MILES EAST OF CAPE FEAR AND 40-45 MILES EAST OF MYRTLE BEACH AND GEORGETOWN. THIS TROUGH SHOULD WEAKEN AND SHIFT EAST AND FARTHER OFFSHORE OVERNIGHT AS AN UPPER LEVEL TROUGH PASSES OVERHEAD AFTER MIDNIGHT. WINDS EAST OF THE TROUGH AXIS ARE GENERALLY E-NE IN THE 8-12 KNOT RANGE...WHILE EAST OF THE TROUGH OVER THE OFFSHORE WATERS THEY ARE SOUTHEAST NEAR 15 KNOTS AT THE FRYING PAN SHOALS BUOY WITH GUSTS TO 17 KNOTS. SEAS HAVE BUILT TO 4 FT OFFSHORE AND TO 2.5 FEET AT THE BUOY JUST SOUTH OF CAPE FEAR. SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 3 PM FRIDAY...A COASTAL TROUGH WILL BISECT THE WATERS ON SAT. THIS TROUGH WILL LIFT N OF THE AREA SAT NIGHT AND DISSIPATE. A COLD FRONT WILL APPROACH FROM THE W SUN AND SUN NIGHT. THE APPROACH OF THIS FRONT WILL GRADUALLY TIGHTEN WHAT WILL OTHERWISE BE A SLACK GRADIENT THIS WEEKEND. THE STRONGEST WINDS ARE EXPECTED SUN NIGHT. THE WINDS WILL BE LIGHT ENE TO E SAT. THE DIRECTION WILL VEER TO SE SAT NIGHT AND TO S ON SUN. WINDS WILL EVENTUALLY COME AROUND TO SW MON MORNING. WIND SPEEDS WILL REACH UP TO 15 TO 20 KT SUN NIGHT. SEAS WILL BE 2 TO 3 FT SAT THROUGH SUN AND THEN BUILD TO 4 TO POSSIBLY 5 FT SUN NIGHT. AN 8 TO 10 SECOND SE SWELL WILL BECOME MORE SIGNIFICANT LATE SUN AND SUN NIGHT. LONG TERM /MONDAY THROUGH WEDNESDAY/... AS OF 3 PM FRIDAY...THE MAIN FEATURE FOR THE MARINE COMMUNITY WILL BE THE FRONT THAT MOVES ACROSS THE WATERS EARLY IN THE PERIOD. THE TIMING REMAINS CONFIDENCE CHALLENGED BUT FOR NOW IT LOOKS LIKE A LATE AFTERNOON WIND SHIFT FROM THE SOUTHWEST TO WEST. NOT THE MOST DYNAMIC OF SYSTEMS SO WINDS WILL TAKE SOME TIME...BY TUESDAY MORNING TO REACH MARGINAL SMALL CRAFT CRITERIA WITH A 20-25 KNOT RANGE. WINDS HAVE A GOOD CHANCE TO STAY ELEVATED AS COLD AIR ADVECTION LAGS WELL BEHIND THE FRONT AND WILL PROBABLY HOVER AROUND 20 KNOTS THROUGH THE END OF THE PERIOD. SEAS WILL BUILD WITH THE WINDS FROM INITIAL VALUES OF 2-4 FEET TO 4-7 FEET BY THE END OF THE PERIOD. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...TRA SHORT TERM...RJD LONG TERM...SHK AVIATION...BJR
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
937 PM EST FRI NOV 15 2013 .SYNOPSIS... MOISTURE INCREASES FROM SOUTHWEST...AS DISTURBANCE ALOFT PASSES TONIGHT. WARMING TREND THROUGH THE WEEKEND. STRONG COLD FRONT CROSSES SUNDAY NIGHT. IN FAST FLOW ALOFT...GUSTY SHOWERS LIKELY. && .NEAR TERM /THROUGH SATURDAY/... UPDATE... ENDED THE POPS QUICKER IN THE OVERNIGHT PERIOD PER LOCAL WRF MODELS AND THE HRRR MODEL. RAIN WEST OF THE TUG FORK RIVER IS MORE SCATTERED IN NATURE...AND WILL SEE THIS TREND MOVING INTO THE WEST VIRGINIA COAL FIELDS IN THE NEXT COUPLE OF HOURS. PREVIOUS DISCUSSION... RADAR AND SATELLITE IMAGES INDICATE SHOWERS STRUGGLING TO REACH THE GROUND ACROSS EASTERN KY THIS AFTERNOON. VERY DRY AIR MASS REMAINS IN PLACE PRODUCING VIRGA FOR THE MOST PART. BELIEVE...THE COLUMN WILL CONTINUE TO MOISTEN...MAKING FEW OF THESE LIGHT SHOWERS TO AFFECT THE EASTERN MOUNTAINS LATER THIS EVENING AND TONIGHT. BREEZY FLOW WILL SUBSIDE LATER TONIGHT AND BECOME MORE SOUTHERLY OVERNIGHT. ADDITIONAL LIGHT SHOWERS WILL BE POSSIBLE ACROSS THE SOUTHERN COAL FIELDS OF WV EARLY SATURDAY. KEPT POPS REACHING LIKELY THIS EVENING ACROSS THE SOUTHEAST HALF OF OUR CWA. MINOR CHANGES TO TEMPERATURES NEEDED. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/... MODELS ARE IN GOOD AGREEMENT ON THE STRONG COLD FRONT THAT RAPIDLY MOVES ACROSS SUNDAY EVENING AND SUNDAY NIGHT. GIVEN THE ASSOCIATED NEGATIVELY TILTED UPPER TROUGH SWINGING UP THROUGH THE GREAT LAKES WITH A DEEPENING SURFACE LOW...THE MODEL TRENDS OF SPEEDING THE FRONT UP EVEN MORE SEEMS REASONABLE. THE CMC IS EVEN FASTER THAN THE OTHER SWEET OF MODELS...WHICH ONE CANNOT RULE OUT...BUT WILL STICK WITH THE VAST MAJORITY OF GUIDANCE WITH THE TIMING. THIS BRINGS THE FRONT TO THE OHIO RIVER SUNDAY EVENING AND EXITING THE MOUNTAINS AFTER MIDNIGHT SUNDAY NIGHT...WELL BEFORE DAWN MONDAY. IN THIS SYNOPTIC SCENARIO...THE LOW LEVEL WINDS WILL BE QUITE STRONG AND GUSTY MAINLY ALONG AND JUST AHEAD OF THE FRONT...WITH MODEL FORECASTS OF 60 TO 65 KNOTS OF SOUTHWEST WINDS AT 850MB PRECEDING THE FRONT. BEING CLOSER TO THE SURFACE LOW...THESE STRONGEST WINDS WITH THIS SYSTEM WILL BE ACROSS THE NORTHWEST THIRD OF THE AREA SUNDAY AFTERNOON AND SUNDAY EVENING. THERE WILL ALSO BE A BAND OF SHOWERS AND A FEW THUNDERSTORMS AS THE FRONT PASSES THROUGH. GIVEN ALL OF THIS...THE BEST CHANCE OF STRONG AND GUSTY WINDS...POSSIBLY DAMAGING WINDS...WILL BE IN THE CONVECTION ALONG AND JUST AHEAD OF THE FRONT AND ESPECIALLY OVER NORTHWEST PORTIONS OF THE AREA. SPC ALSO HAS A SLIGHT RISK OF SEVERE STORMS SNEAKING IN FROM THE WEST SUNDAY EVENING WITH THE FRONT...WITH THE MAIN THREAT BEING DAMAGING WINDS. THIS IS HIGHLIGHTED IN THE HAZARDOUS WEATHER OUTLOOK PRODUCT. AFTER A DRY AND MILD SATURDAY NIGHT...SUNDAY ITSELF WILL FEATURE A LOT OF CLOUDS AND SCATTERED SHOWERS IN THE WARM ADVECTION AND MOIST SOUTHERLY INFLOW WELL AHEAD OF THE FRONT ITSELF. WHILE CLOUDS WILL HELP LIMIT MIXING WITH THE INCREASING LOW LEVEL WINDS...ONE CANNOT RULE OUT AN ISOLATED DAMAGING GUST IN A SHOWER SUNDAY AFTERNOON... ESPECIALLY NORTHWEST PORTIONS OF THE AREA FOR THE REASONS MENTIONED ABOVE. LOOK FOR TEMPS SUNDAY TO BE WELL ABOVE NORMAL...AROUND 70... DESPITE THE CLOUDS. FRONT BLASTS THRU SUNDAY NIGHT WITH WESTERLY WINDS BRINGING IN A NICE DRY SLOT BY MONDAY MORNING. LOOK FOR A DRY AND A MODESTLY COOLER DAY MONDAY AS MOST OF THE COLD ADVECTION REMAINS NORTH OF US. LATER IN THE DAY MONDAY...AS WINDS DO TURN MORE NORTHWESTERLY...LOOK FOR INCREASED COLD ADVECTION AND UPSLOPE TO BRING A LOW CHANCE OF RAIN SHOWERS IN THE NORTHERN WEST VIRGINIA MOUNTAINS. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... GENERALLY QUIET IN THE EXTENDED. SOME SNOW SHOWERS POSSIBLE ACROSS THE NORTHERN ZONES MONDAY NIGHT AS THE UPPER FLOW TURNS NORTHWESTERLY BRIEFLY. MAINLY ZONAL FLOW MID WEEK WITH SOME UPPER RIDGING TAKING HOLD BY WEEKS END. A CHILLY AIRMASS WILL MODIFY TO NEAR NORMAL BY WEEKS END. && .AVIATION /02Z SATURDAY THROUGH WEDNESDAY/... LIGHT RAIN SHOWERS CURRENTLY OVER THE SOUTHERN COAL FIELDS WILL SPREAD ACROSS THE SOUTHERN AND CENTRAL MOUNTAINS OVERNIGHT. SE OHIO MAY SEE SOME SCATTERED LIGHT SHOWERS BUT WILL REMAIN MOSTLY DRY WITH ABUNDANT CLOUDINESS. VFR CONDITIONS WITH CEILINGS AT 4 TO 6 THSD FEET AND VISIBILITIES DROPPING TO 4 TO 5 MILES IN LIGHT RAIN. WITH SHOWERS BECOMING MORE WIDESPREAD CEILINGS WILL LOWER TO 2000 FEET OVER SOUTHERN MOUNTAIN INCLUDING BKW VICINITY BY 03Z TO 06Z SATURDAY AND COULD LOWER 1 TO 2 THSD FT BKN/OVC 06Z TO 12Z SATURDAY. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z SUNDAY... FORECAST CONFIDENCE: MEDIUM TO HIGH. ALTERNATE SCENARIOS: INTENSITY OF RAIN SHOWERS COULD DETERIORATE CEILINGS AND VISIBILITIES TO IFR OR WORST. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. DATE SAT 11/16/13 UTC 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13 EST 1HRLY 21 22 23 00 01 02 03 04 05 06 07 08 CRW CONSISTENCY M M M M M H M M H H H H HTS CONSISTENCY M M M H H H H H H H H H BKW CONSISTENCY M H H M M M M M M M M H EKN CONSISTENCY H H H M M H H H H H H H PKB CONSISTENCY H H H H H H H H H H H H CKB CONSISTENCY H H H H H H H H H H H H AFTER 00Z SUNDAY... IFR IN STRATUS POSSIBLE ON THE EASTERN SLOPES OF THE WV MOUNTAINS 12Z TO 15Z SUNDAY MORNING...INCLUDING THE GREENBRIER VALLEY. IN FAST FLOW AREA WIDE...IFR ALSO POSSIBLE IN GUSTY RAIN SHOWERS SUNDAY AFTERNOON AND SUNDAY NIGHT...AHEAD OF...AND ALONG COLD FRONT. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...ARJ/JMV/30 NEAR TERM...ARJ/26 SHORT TERM...JMV LONG TERM...30 AVIATION...26/JM
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
518 PM CST FRI NOV 15 2013 .AVIATION... FOR THE 00Z TAFS...THE PRIMARY CONCERNS ARE THE POTENTIAL FOR SHRA TONIGHT...AND WINDS TOMORROW. SHRA WILL BE POSSIBLE AFTER 03Z...THOUGH MORE LIKELY AFTER 06Z...ACROSS THE W AND S TX PANHANDLE. COVERAGE WILL BE LIMITED...SO THERE IS NOT ENOUGH CONFIDENCE TO INCLUDE ANYTHING MORE THAN VCSH AT THIS TIME. HOWEVER...IF A SHRA DOES DIRECTLY IMPACT A TERMINAL...GIVEN VERY DRY LOW LEVELS...THERE IS A THREAT FOR DRY DOWNBURSTS LEADING TO GUSTY AND VARIABLE WINDS. TOMORROW...WINDS WILL INCREASE SHORTLY AFTER 15Z...APPROACHING 30G40KT. HOWEVER...THERE IS ONE CONCERN THAT CLOUDS WILL NOT CLEAR OUT IN TIME TO ALLOW MAXIMUM MIXING. EVEN GRANTING THE CLOUDS ARE SLOWER TO CLEAR OUT...AGREE WITH THE PREVIOUS SHIFT THAT A FEW GUSTS NEAR 40KT ARE LIKELY AT KAMA AND KDHT. FOR NOW HOWEVER...WILL NOT ISSUE AN AWW FOR THE WINDS TOMORROW IN CASE AN AWW WILL BE NEEDED THIS EVENING DUE TO THE GUSTY WINDS WITH SHRA. VFR CONDITIONS ARE EXPECTED WITH THE EXCEPTION OF A SMALL THREAT OF DECREASED VISIBILITIES DUE TO BLOWING DUST IN THE STRONGEST WINDS. JOHNSON && .PREV DISCUSSION... /ISSUED 232 PM CST FRI NOV 15 2013/ DISCUSSION... FORECAST CHALLENGES OVER THE NEXT 24 HOURS INCLUDE CHANCES FOR ANY CONVECTION TONIGHT AND WIND ADVISORY PROSPECTS FOR SATURDAY. AGREE WITH WFO LUBBOCK AS THE HRRR AND EVEN THE RUC SHOWING PRECIP MOVING NORTH AND EAST OUT OF NEW MEXICO THIS EVENING THROUGH TONIGHT ACROSS MAINLY PARTS OF THE TEXAS PANHANDLE. THIS CONVECTION ASSOCIATED WITH A SHORTWAVE LOCATED OVER WESTERN AND SOUTHERN NEW MEXICO AND FORECAST TO LIFT NORTH AND EAST INTO THE SOUTHWEST AND CENTRAL TEXAS PANHANDLE AFTER 00Z AND 03Z SATURDAY. CONFIDENCE NOT HIGH ENOUGH TO MENTION THUNDER...BUT WILL INTRODUCE ISOLATED SHOWERS FOR THE TONIGHT PERIOD. CONSIDERABLE MID AND HIGH LEVEL CLOUDINESS TONIGHT INTO SATURDAY MAY PUT A DAMPER ON MIXING THE STRONGER WINDS ALOFT AFTER 15Z TO 17Z SATURDAY...HOWEVER AGREE THAT WIND ADVISORY CRITERIA MAY BE MET ON THE CAPROCK BY 18Z SATURDAY. CONFIDENCE JUST NOT HIGH ENOUGH ON TIMING AND LOCATION TO ISSUE A WIND ADVISORY AT THIS TIME. FEEL THAT A NARROW WINDOW OF WIND ADVISORY CRITERIA POSSIBLE BETWEEN ABOUT 17Z AND 21Z SATURDAY...WITH WIND SPEEDS GRADUALLY DECREASING THROUGH THE REMAINDER OF THE AFTERNOON. COLD FRONT EXPECTED TO PUSH SOUTH AND WEST THROUGH THE PANHANDLES DURING THE DAY SUNDAY BRINGING COOLER CONDITIONS EARLY NEXT WEEK. MODERATING TEMPERATURES BY THE MIDDLE OF NEXT WEEK BEFORE ANOTHER COLD FRONT MOVES THROUGH THE FORECAST AREA LATE NEXT WEEK. MEDIUM RANGE MODELS INDICATING POSSIBLE PRECIP CHANCES BY THURSDAY NIGHT OR FRIDAY MAINLY ACROSS THE EASTERN SECTIONS OF THE PANHANDLES AS AN UPPER TROUGH APPROACHES FROM THE FOUR CORNERS AND SOUTHERN ROCKIES. WILL HOLD OFF INTRODUCING ANY POPS IN THE THURSDAY TO FRIDAY TIME FRAME...BUT WILL BUMP UP POPS TO AROUND 10 PERCENT OR SO. SCHNEIDER FIRE WEATHER... MARGINAL ELEVATED FIRE WEATHER CONDITIONS WILL PERSIST UNTIL AROUND SUNSET THIS EVENING WITH THE 20 FOOT WIND SPEEDS GRADUALLY SUBSIDING BUT STILL REMAINING IN THE 15 TO 20 MPH RANGE WITH SOME HIGHER GUSTS. 20 FOOT DOWNSLOPING SOUTHWESTERLY WINDS WILL INCREASE AFTER MID TO LATE MORNING TO AROUND 20 TO 30 MPH WITH HIGHER GUSTS AND MINIMUM AFTERNOON HUMIDITIES FALLING TO NEAR 20 PERCENT. ALTHOUGH ONLY MARGINAL FIRE WEATHER CONDITIONS ARE EXPECTED SATURDAY...THE STRONG WINDS ALONE MAY JUSTIFY ISSUING A FIRE DANGER STATEMENT FOR ELEVATED FIRE WEATHER CONDITIONS. ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS ARE NOT EXPECTED SUNDAY THROUGH LATE NEXT WEEK AS EITHER THE MINIMUM AFTERNOON RELATIVE HUMIDITIES REMAIN AT OR ABOVE 20 PERCENT OR THE 20 FOOT WIND SPEEDS REMAIN BELOW 15 TO 20 MPH. SCHNEIDER && .AMA WATCHES/WARNINGS/ADVISORIES... TX...NONE. OK...NONE. && $$ 16/02
AREA FORECAST DISCUSSION
NWS SPOKANE WA
653 PM PST Fri Nov 15 2013 .SYNOPSIS... A strong weather system will spread rain and snow into most of the region tonight and Saturday with accumulating snow in the mountains as well as some northern valley locations. The weather will trend slightly drier on Sunday into early Monday...except near the Canadian border. A much wetter but warmer weather system will move into the area late Monday and continue through Tuesday and Wednesday. && .DISCUSSION... Looking at recent HRRR runs and some other later model guidance felt it appropriate to delay the start of the wind advisory a few hours to 10 PM PST rather than its earlier 7 PM start as the jet is just a bit slow entering the area. /Pelatti && .AVIATION... 00Z TAFs: This remains a difficult and low confidence forecast due to a moist winter storm continuing to sweep in from the northwest...at least for the eastern forecast sites. For MWH and EAT...confidence is quite good that both sites will remain at VFR conditions due to downslope flow off the Cascades. The remaining sites will see a much less confident forecast as precipitation type will remain problematic until event ends around 10z. We are confident that the cigs will remain mvfr at best and ifr at worst for GEG SFF COE PUW with nearly continuous precipitation. What the precip falls as will be the difficult question to answer. Evening temperatures and moisture sounding showed freezing level right around 3000 ft...which suggests the higher sites...GEG PUW and COE...could remain a rain snow mix or all snow through the entire time period. The more snow there is the worse the visibilities will be with values commonly at 1.5 miles or less. The precipitation will depart the forecast sites just before sunrise...but given the moist atmosphere and southwest low-level flow we suspect low ceilings will remain in place through at least 18z. Conditions should improve in the afternoon...but whether they improve to vfr levels is not a foregone conclusion. fx && .PRELIMINARY POINT TEMPS/POPS... Spokane 33 36 27 40 31 42 / 100 60 10 40 40 10 Coeur d`Alene 33 36 25 38 29 41 / 100 90 20 50 50 20 Pullman 33 37 30 40 32 43 / 100 90 10 40 40 30 Lewiston 38 40 34 46 34 47 / 90 80 20 30 30 20 Colville 34 38 21 37 27 41 / 100 60 20 50 60 20 Sandpoint 33 36 24 37 30 40 / 100 100 40 70 70 50 Kellogg 31 33 26 35 27 39 / 100 100 70 50 60 40 Moses Lake 37 45 29 47 32 47 / 40 10 0 10 10 10 Wenatchee 35 43 30 43 33 46 / 10 10 0 10 10 10 Omak 30 40 26 39 30 43 / 20 10 0 30 20 10 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...Winter Weather Advisory until 10 AM PST Saturday for Coeur d`Alene Area. Winter Storm Warning until 4 AM PST Sunday for Central Panhandle Mountains-Northern Panhandle. Winter Weather Advisory until 4 PM PST Saturday for Lewis and Southern Nez Perce Counties. WA...Winter Weather Advisory until 4 PM PST Saturday for Northeast Mountains-Okanogan Highlands. Wind Advisory from 10 PM this evening to 7 AM PST Saturday for Lower Garfield and Asotin Counties-Upper Columbia Basin- Washington Palouse. Winter Weather Advisory until 4 PM PST Saturday for Northeast Blue Mountains. && $$
AREA FORECAST DISCUSSION
NWS SPOKANE WA
1000 AM PST Thu Nov 14 2013 .SYNOPSIS... Areas of dense fog will continue over the Lewiston area into this afternoon. A weak weather system today may produce a few showers mainly over the mountains. A major weather change is expected to arrive Friday as a strong weather system from the northwest brings rain and snow to most of the region. Heavy snow accumulations are possible in the mountains...as well as the northern valleys and Idaho Panhandle. Colder air will seep in from Canada on Saturday behind a cold front with much cooler temperatures through early next week. && .DISCUSSION... Update...A weak weather system will track across the area today bringing mainly mid level clouds above areas of low level stratus that lingers cross the area due to a moist boundary layer. Models show a pocket of mid level instability over Northwest Washington this morning tracking into south Central Washington this afternoon. In addition the best lift will also track in this area giving the Cascade crest the best chance of showers with a few showers also possible along the East Slopes. With only weak upslope into the Idaho Panhandle, and best dynamic tracking well west of this area...GFS, NAM, and HRRR show very little shower activity and shower coverage has been lowered for Sandpoint, Kellogg, and Lookout Pass. Overall fog coverage is diminishing this morning but remains dense in the Lewiston area. This weak system passing through today may allow for some improvement...but this will likely be a slow process given fog and stratus is trapped in the valley. Thus areas of fog has been extended into the afternoon and have adjusted highs down into the mid 40s. && .AVIATION... 18Z TAFs: A moist boundary layer will linger though 18z Friday resulting in continued areas of stratus. Most of the stratus has lifted into 3000-4000 ft AGL except KLWS where VLIFR persists. Model guidance is not handling this well so confidence is low. The fog should begin to lift after 22z with a weak system passing through and then mid level clouds should prevent fog from reforming tonight. Again however this is a low confidence forecast. As the next system approaches tonight south-southwest winds will aid in increasing low level moisture with IFR/MVFR stratus likely increasing around KGEG/KSFF/KCOE/KPUW by 12z. JW && .PRELIMINARY POINT TEMPS/POPS... Spokane 45 33 37 32 33 24 / 10 10 100 100 90 30 Coeur d`Alene 46 34 37 32 32 23 / 10 20 90 100 100 30 Pullman 46 32 38 33 35 26 / 10 10 90 100 90 30 Lewiston 46 35 44 35 39 30 / 10 10 50 90 80 30 Colville 45 33 38 32 34 17 / 10 10 100 100 90 30 Sandpoint 44 33 36 31 32 19 / 20 20 100 100 100 30 Kellogg 41 34 36 31 32 21 / 20 30 90 100 100 70 Moses Lake 49 31 45 34 41 28 / 10 0 20 20 10 10 Wenatchee 50 35 45 31 41 28 / 10 0 10 20 10 10 Omak 47 32 42 29 36 21 / 10 0 20 30 20 10 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...Winter Storm Watch from Friday morning through late Saturday night for Central Panhandle Mountains. Winter Storm Watch from late tonight through Saturday afternoon for Northern Panhandle. WA...Winter Storm Watch from Friday morning through late Saturday night for Northeast Blue Mountains. Winter Storm Watch from late tonight through Saturday afternoon for Northeast Mountains-Okanogan Highlands. && $$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
322 PM CST THU NOV 14 2013 .SHORT TERM...(TONIGHT THROUGH FRIDAY NIGHT) 322 PM CST THU NOV 14 2013 CONCERNS THROUGH THE SHORT TERM PERIOD INCLUDE RAIN CHANCES INTO THIS EVENING AND AREAS OF FOG OVERNIGHT. WATER VAPOR COUPLED WITH RAP 500MB ANALYSIS SHOWING A MID-LEVEL TROUGH ROTATING EAST OUT OF THE DAKOTAS TOWARD THE UPPER MISSISSIPPI RIVER VALLEY REGION. RAP SHOWING RIGHT ENTRANCE REGION OF 300MB JET COUPLED WITH FAIRLY STRONG 700-500MB FRONTOGENESIS ACROSS OUR REGION AHEAD OF THE APPROACHING MID-LEVEL WAVE. RESULT...PER REGIONAL RADAR MOSAIC AND SURFACE OBSERVATION WAS A NARROW BAND OF LIGHT RAIN EXTENDING FROM NORTHEAST WI THROUGH WINONA AND LA CROSSE...TO PORTIONS OF SOUTHEAST MN/NORTH CENTRAL IA. CLOUDS AND LIGHT SOUTHERLY SURFACE FLOW KEEPING TEMPERATURES IN CHECK IN THE UPPER 30S TO THE MID 40S. WILL BE WATCHING THE MID-LEVEL TROUGH TO SLIP EAST ACROSS THE AREA THIS EVENING/OVERNIGHT WITH BETTER FRONTOGENESIS EXITING EAST EARLY ON IN THE EVENING. THIS SHOULD BRING AND END TO ANY LIGHT RAIN ACTIVITY. A WEAK SURFACE TO MID-LEVEL RIDGE OF HIGH PRESSURE BUILDS IN TOWARD MORNING. AS A RESULT...EXPECTING A GENERAL CLEARING TREND LATER THIS EVENING THROUGH THE REST OF THE NIGHT. CONCERN THEN BECOMES FOG POTENTIAL WITH RADIATIONAL COOLING AND RELATIVELY MOIST LOWER BOUNDARY LAYER GIVEN TODAY/S LIGHT RAINFALL. WENT WITH AREAS OF FOG IN THE MAIN RIVER STEMS AND PATCH FOG ELSEWHERE. WILL HAVE TO WATCH THIS CLOSE OVERNIGHT AS ANY FURTHER CLEARING/RADIATIONAL COOLING COULD LEAD TO POCKETS OF DENSE FOG IN THE MORNING AROUND COMMUTE TIME. FOR FRIDAY...MODEL SOUNDING SHOWING THE INVERSION BREAKING AROUND NOON WITH SOUTHERLY FLOW KICKING IN ON THE BACKSIDE OF THE DEPART HIGH AND IN ADVANCE OF APPROACHING TROUGH OVER THE HIGH PLAINS. UNDER PARTLY CLOUDY SKIES...LOOK FOR TEMPERATURES TO MODERATE INTO SLIGHTLY ABOVE SEASONAL NORMAL TERRITORY AS READING REACH INTO THE UPPER 40S TO THE LOWER 50S. SOUTHERLY SURFACE FLOW CONTINUES INTO FRIDAY NIGHT AHEAD OF THE APPROACHING TROUGH WITH INCREASING 290K ISENTROPIC LIFT/850MB MOISTURE TRANSPORT. THIS STRONGEST OF THIS FORCING WILL REMAIN JUST TO OUR WEST THROUGH 12Z SATURDAY MORNING FOR BEST CHANCE OF COLUMN SATURATION/RAINFALL. WENT WITH A SMALL/20 PERCENT CHANCE OF RAIN WEST OF A CHARLES CITY TO ROCHESTER LINE AFTER 3 AM SATURDAY. SOUTHERLY FLOW/INCREASING CLOUDS WILL KEEP TEMPERATURES UP IN THE MID-UPPER 30S. .LONG TERM...(SATURDAY THROUGH THURSDAY) 330 PM CST THU NOV 14 2013 LOOK FOR A RAPID EXPANSION OF RAIN ACROSS THE AREA SATURDAY MORNING AS BROADSCALE SOUTHERLY FLOW/LIFT/MOISTURE TRANSPORT MOVE SQUARELY INTO THE REGION. FAIRLY MILD CONDITIONS WITH HIGHS IN THE UPPER 40S TO MIDDLE 50S CAN BE EXPECTED SATURDAY. MILD/MOIST CONDITIONS ALONG WITH DYNAMICS/MID-LEVEL STEEPENING LAPSE RATES WILL ALSO PRODUCE A SMALL CHANCE OF THUNDER BY AFTERNOON. LOOK FOR THE LIKELIHOOD OF RAIN AND POCKETS OF THUNDER TO CONTINUE ACROSS THE AREA SATURDAY NIGHT INTO SUNDAY AS STRONGER SURFACE CYCLOGENESIS TAKES PLACE AND MOVES NORTHEAST ACROSS THE UPPER MISSISSIPPI RIVER VALLEY REGION. STILL SOME UNCERTAINTY BETWEEN THE MODELS ON INTENSITY AND EXACT TRACK OF THE LOW...BUT ALL POINT TOWARD OUR AREA BEING IN THE WARM SECTOR OF THE LOW...ESPECIALLY THE ECMWF. THE NAM PRODUCES 1200-1500J/KG OF 0-3KM ML MUCAPE SUNDAY ACROSS PORTIONS OF FAR SOUTHWEST WI IN THE WARM SECTOR WITH AMPLE BULK SHEAR. GIVEN THIS SIGNAL AND SYSTEM DYNAMICS..WILL HAVE TO WATCH FOR A SEVERE THUNDERSTORM POTENTIAL ACROSS THAT AREA. OTHERWISE...MODEL CONSENSUS PRODUCES HIGH TEMPERATURES SUNDAY IN THE UPPER 40S TO THE MIDDLE 50S. GFS AND ECMWF CONTINUE AT ODDS ON MOVEMENT/INTENSITY OF THE SURFACE LOW THROUGH SUNDAY NIGHT...WITH THE ECMWF REMAINING SLOWER/MORE INTENSE AS IT LIFTS INTO UPPER MICHIGAN. THIS WOULD PRODUCE DEFORMATION RAIN CHANGING TO POSSIBLY MEASURABLE SNOW FOR MUCH OF THE AREA. THE GFS ON THE OTHERHAND IS MORE OPEN/PROGRESSIVE WITH THE LOW...LIFTING THE PRECIPITATION OUT OF THE AREA BY MIDNIGHT SUNDAY NIGHT. WILL GO WITH A MODEL CONSENSUS FOR NOW UNTIL THERE IS BETTER AGREEMENT...WHICH PRODUCES A 30-40 PERCENT CHANCE OF RAIN EARLY...CHANGING OVER TO SNOW. COLD AIR ADVECTION ON BLUSTERY NORTHWEST WINDS EXPECTED ON MONDAY BEHIND THE DEPARTING LOW. A FEW SNOW SHOWERS WILL ALSO BE POSSIBLE ACROSS NORTH CENTRAL WI IN THIS COLD CYCLONIC FLOW. LOOK FOR HIGHS ONLY IN THE 30S. A FAIRLY STRONG RIDGE OF HIGH PRESSURE MOVES ACROSS THE AREA MONDAY NIGHT THROUGH WEDNESDAY FOR A QUIET PERIOD. TEMPERATURES WILL REMAIN CHILLY THOUGHT WITH HIGHS IN THE 30S AND LOWS IN THE TEENS AND LOWER 20S. NEXT CHANCE OF PRECIPITATION FOR THE AREA LOOKS TO BE ON THURSDAY AS WARM AIR ADVECTION AND WEAK MOISTURE TRANSPORT TAKE PLACE AHEAD OF A TROUGH OF LOW PRESSURE MOVING OUT OF THE NORTHERN PLAINS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) 1144 AM CST THU NOV 14 2013 BROAD TROUGH PASSING THROUGH NORTHERN STATES HAS CREATED MID LEVEL FRONTOGENETIC BAND OF LIGHT RAIN FROM NORTHERN WISCONSIN BACK TO NORTHWEST IOWA. VFR CONDITIONS PREVAIL EVEN WITH THIS. BAND SHOULD CONTINUE TO PROGRESS EAST THROUGH THE DAY WITH MODEL HINTS OF WEAKENING IN FORCING AS IT DOES. BESIDES OCCASIONAL LIGHT RAIN FOR AN HOUR OR TWO...MINIMAL IMPACT. WEAKENING NATURE OF PASSING SYSTEM LIKELY WILL NOT CREATE MUCH OF A WIND SHIFT EITHER. WITH TEMPERATURES BEING HELD BACK A BIT TODAY...AND SMALL AMOUNT OF RAIN FALLING...COULD SEE ENOUGH LOW LEVEL SATURATION AS WINDS BECOME LIGHTER TONIGHT FOR PATCHY FOG. HIGHEST RISK APPEARS TO BE ALONG MISSISSIPPI RIVER AND EAST. IF FOG DOES FORM IT SHOULD BE SHALLOW AND BURN OFF QUICKLY FRIDAY MORNING. THIS WILL HAVE TO BE WATCHED THIS EVENING BUT FOR NOW KEPT FOG IN VICINITY OF TAF SITES. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...DAS LONG TERM...DAS AVIATION...SHEA
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE

.SHORT TERM...TONIGHT AND FRIDAY ISSUED AT 248 PM CST THU NOV 14 2013 LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A SURFACE TROUGH/WARM FRONT MOVING EAST ACROSS THE NORTHERN MISSISSIPPI VALLEY EARLY THIS AFTERNOON. ELEVATED FRONTAL ZONE/RIGHT REAR QUAD OF JET STREAK IS PRODUCING A BAND OF SPRINKLES OR VERY LIGHT RAIN FROM NORTHWEST IOWA TO NORTHEAST WISCONSIN. A FEW OBS OVER SW WISCONSIN ARE SHOWING THE RAIN REACHING THE GROUND...AND THINK THE SAME CAN BE SAID OVER CENTRAL AND NORTHEAST WISCONSIN. THIS BAND SHOULD CONTINUE TO MOVE SOUTHEAST OVER THE REST OF THE AFTERNOON AND REACH THE FOX VALLEY BEFORE 00Z. CLEARING SKIES ARE WORKING INTO WESTERN WISCONSIN BEHIND THE FRONT WITH TEMPERATURES RISING INTO THE MIDDLE 50S. THEN ANOTHER AREA OF STRATUS IS WORKING SOUTHEAST OVER NORTH DAKOTA AND NORTHERN MINNESOTA. FORECAST CONCERNS INCLUDE CLOUD AND LIGHT PRECIP TRENDS...FOLLOWED BY TEMPS. TONIGHT...THE SHORTWAVE TROUGH MOVING INTO THE WESTERN GREAT LAKES WILL MOVE ACROSS THE LAKE SUPERIOR REGION TONIGHT. IT WILL PUSH A ELEVATED FRONTAL ZONE ACROSS NORTHEAST WISCONSIN EARLY THIS EVENING BEFORE EXITING BY MIDNIGHT. HAVE KEPT A CHANCE OF SPRINKLES GOING INTO THE EVENING TO ACCOUNT FOR UPPER DIVERGENCE AND WEAK CONVERGENCE ALONG THE FRONTAL ZONE. ONCE MID AND UPPER CLOUDS DEPART EAST-CENTRAL WISCONSIN LATE IN THE EVENING...MODELS SHOW MID-LEVEL DRYING TAKING PLACE ACROSS THE REGION. THINK THIS WILL LEAD TO CLEARING ACROSS ALL BUT FAR N-C WISCONSIN. AREA OF CLOUDS ACROSS NORTHERN MINNESOTA/NORTH DAKOTA LOOK TO AT LEAST GRAZE NORTHERN WISCONSIN...SO HAVE KEPT PARTLY TO MOSTLY CLOUDY CONDITIONS GOING THERE THROUGH THE NIGHT. STATISTICAL GUIDANCE SHOWS LOW STRATUS OR FOG DEVELOPING WHERE SKIES CLEAR OUT...AND WOULD BE POSSIBLE IF DEWPOINTS CAN RISE INTO THE LOWER OR MIDDLE 30S..LIKE THEY DID OVER MINNESOTA. THINK THIS WILL OCCUR ACROSS OUR AREA LATE THIS AFTERNOON AND EVENING AS THE SURFACE TROUGH MOVES THROUGH...BUT THERE MAY BE TOO MUCH WIND FOR FOG TO DEVELOP...SO LOW STRATUS IS A BETTER OPTION. AFTER PARTIALLY CLEARING SKIES THIS EVENING...WILL INCREASE CLOUDS LATE TONIGHT WITH ANTICIPATION OF STRATUS DEVELOPING. THE SREF SUPPORTS THIS IDEA. CONTINUED TO GO WITH THE WARMER SIDE OF TEMPS TONIGHT...WHICH PLACES THEM IN THE UPPER 20S TO MID 30S. FRIDAY...WEAK ARCTIC FRONT WILL MOVE ACROSS WESTERN LAKE SUPERIOR AND THE UPPER PENINSULA DURING THE MORNING...BUT LOSE DEFINITION ACROSS NORTHERN WISCONSIN. RESIDUAL MOISTURE ALONG THE FRONT WILL LIKELY LEAD TO SCT OR BKN CLOUD COVER ACROSS THE NORTH. THESE CLOUDS SHOULD LIFT OFF TO THE NORTHEAST DURING THE AFTERNOON. ELSEWHERE...ANY SHALLOW FOG/STRATUS SHOULD DISSIPATE EARLY...WHICH WILL LEAVE A MOSTLY SUNNY OR PARTLY CLOUDY CONDITIONS FOR MUCH OF THE DAY. HIGHS RANGING THROUGH THE 40S. .LONG TERM...FRIDAY NIGHT THROUGH THURSDAY ISSUED AT 248 PM CST THU NOV 14 2013 PLENTY OF CONCERNS IN THE LONG TERM PORTION OF THE FORECAST...MAINLY CENTERED AROUND A SECONDARY LOW PROGGED TO MOVE ACROSS THE REGION LATE IN THE WEEKEND. THE ECMWF AND GEM ARE SLOWER THAN THE GFS IN EJECTING A STRONG SHORTWAVE TROUGH/SURFACE LOW ACROSS THE PLAINS AND GREAT LAKES. LOOKING AT HPC DISCUSSIONS...THEY FAVOR USING THE ECMWF ENSEMBLE MEAN...WHICH HAS MORE SUPPORT FROM OTHER OPERATIONAL MODELS THAN THE GFS/GFS ENSEMBLE MEAN. NOT CONVINCED SLOWER IS BETTER IN THIS INSTANCE SINCE THERE IS AN ABSENCE OF BLOCKING ACROSS THE CONTINENT AND THERE IS A 150KT RELATIVELY ZONAL JET UPSTREAM OF THE TROUGH. THIS WOULD ARGUE FOR A MORE PROGRESSIVE PATTERN. SO WITH CONFLICTING SIGNALS...GUESS ITS BEST TO GO WITH AN ECMWF/GFS BLEND TO MITIGATE THESE DIFFERENCES. FRIDAY NIGHT THROUGH SUNDAY...MID AND HIGH CLOUDS WILL BE ON THE INCREASE FRIDAY NIGHT AS LEAD SHORTWAVE ENERGY EJECTS INTO THE CENTRAL PLAINS. WITH INCREASING CLOUDS AND A TIGHTENING PRESSURE GRADIENT...WILL SIDE ON THE WARM SIDE OF GUIDANCE. THE LEAD SHORTWAVE TROUGH WILL MOVE NORTHEAST AND ACROSS WISCONSIN DURING THE AFTERNOON. AHEAD OF THE TROUGH...A 50+KT LLJ WILL DEVELOP AND TRANSPORT MOISTURE ACROSS THE STATE. WITH DECENT -DIVQ IN THE MID AND UPPER LEVELS...AND STRONG MOISTURE ADVECTION IN THE LOW LEVELS...RAIN IS A SOLID BET LATE SATURDAY MORNING AND THROUGH THE AFTERNOON. WILL INCREASE POPS. THE MAIN AREA OF RAIN WILL BE EXITING TO THE NORTHEAST OVER THE COURSE OF SATURDAY EVENING AS THE REGION GETS TEMPORARILY DRY SLOTTED. PLENTY OF LOW LEVEL MOISTURE WILL BE LEFT THOUGH...AND WITH WEAK WARM ADVECTION CONTINUING...SHOULD SEE PLENTY OF CLOUDY COVER AND MAYBE PATCHY DRIZZLE/FOG LEFT OVER. PREVIOUS SHIFT ALREADY HAD THIS COVERED PRETTY WELL. THE SECONDARY LOW WILL THEN ORGANIZE ACROSS THE PLAINS AND LIFT NE ACROSS THE SOUTHEAST HALF OF WISCONSIN ON SUNDAY. SHOULD SEE ANOTHER ROUND OF PRECIP ARRIVE WITH THIS LOW...HEAVIEST ACROSS THE SOUTHEAST HALF OF THE FORECAST AREA. PRECIP TYPE LOOKS TO REMAIN ALL LIQUID. NO SIGNIFICANT CHANGES TO TEMPS. REST OF THE FORECAST...THE SURFACE LOW WILL EXIT SUNDAY NIGHT AND A CHANGE OVER TO SNOW IS ANTICIPATED AS COLDER AIR RUSHES IN BEHIND THE CYCLONE. CANNOT GET EXCITED ABOUT ACCUMS THOUGH...UNTIL MORE CONSENSUS DEVELOPS IN THE DETAILS. WINDY CONDITIONS WILL ACCOMPANY THE COLD ADVECTION SUNDAY NIGHT INTO MONDAY. IF THE SLOWER SOLUTION WORKS OUT...WIND HEADLINES WILL BE POSSIBLE. CLOUDY AND COLD ON MONDAY WITH HIGHS RETURNING TO THE 20S AND 30S. THEN A SLOW WARMING TREND ENSUES MID-WEEK ONWARD. && .AVIATION...FOR 18Z TAF ISSUANCE ISSUED AT 1151 AM CST THU NOV 14 2013 VFR CONDITIONS OVER THE TAF PERIOD...BUT NOT WITHOUT SOME CONCERNS. WEAK FRONT WILL GENERATE SCATTERED SPRINKLES OR VERY LIGHT SHOWERS THIS AFTERNOON AND EARLY THIS EVENING. BEHIND THIS FRONT...AT LEAST PARTIAL CLEARING IS EXPECTED...WHICH LEADS TO THE POSSIBILITY OF LOW STRATUS OR FOG DEVELOPING. DEWPOINTS ARE STILL RATHER LOW ALTHOUGH THEY ARE INCREASING GRADUALLY. NOT SURE IF THEY WILL INCREASE ENOUGH THOUGH...SO TRENDED VSBYS DOWN A LITTLE AT THE MORE FOG PRONE AREAS AT AUW AND RHI. MVFR STRATUS OVER NORTHERN MINNESOTA IS MOVING EAST AND COULD GRAZE NORTH-CENTRAL WISCONSIN. IF IT HOLDS TOGETHER...THE FOG CONCERN WILL DIMINISH. && .MARINE... ISSUED AT 248 PM CST THU NOV 14 2013 WEST TO NORTHWEST GALES ARE EXPECTED LATE SUNDAY NIGHT INTO MONDAY NIGHT AS A STRONG AREA OF LOW PRESSURE MOVES AWAY FROM THE AREA. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....MPC LONG TERM......MPC AVIATION.......MPC MARINE.........MPC
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1046 PM CST WED NOV 13 2013 UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE .SHORT TERM...TONIGHT AND THURSDAY ISSUED AT 251 PM CST WED NOV 13 2013 LOW PRESSURE OVER NORTHWEST ONTARIO COUPLED WITH STRONG HIGH PRESSURE CENTERED OVER KENTUCKY HAS LEAD TO STRONG PRESSURE GRADIENT OVER THE FORECAST AREA LATE THIS AFTERNOON. SO FAR MAX WINDS GUSTS HAVE BEEN GENERALLY IN THE 35 TO 40 MPH RANGE ALONG THE LAKESHORE COUNTIES FROM MANITOWOC TO DOOR COUNTY. HRRR AND RAP SUGGEST THAT GRADIENT WILL LIKELY STRENGTHEN A BIT MORE AS WE APPROACH THE EARLY EVENING...THEN SLACKEN SOMEWHAT AFTER MIDNIGHT. THUS EXPECT SOUTHWESTERLY WIND GUSTS OF SIMILAR MAGNITUDE TO CONTINUE UNTIL ABOUT 03Z THIS EVENING. OVER DOOR COUNTY MAX WIND GUSTS EXPECTED TO BE SOMEWHAT HIGHER...CLOSER TO 45 MPH INTO EARLY EVENING. GENERALLY FAIR SKIES OVERNIGHT TONIGHT WITH LOWS WARMER THAN LAST NIGHT MAINLY IN THE 25 TO 30 DEGREE RANGE. LATEST SUITE OF MODEL GUIDANCE CONTINUES TO ADVERTISE PASSAGE OF RELATIVELY WEAK AND PROGRESSIVE SHORTWAVE DISTURBANCE THURSDAY AFTERNOON WITHIN FLAT ZONAL FLOW. PRIMARY FORCING WITH THIS SYSTEM MAINLY ASSOCIATED WITH RRQ OF UPPER JET AND SOME MODEST FRONTEGENETIC FORCING. GUIDANCE HAS BEEN FAIRLY CONSISTENT IN DEPICTING A RELATIVELY NARROW BAND OF MOISTURE AHEAD OF WEAK SURFACE FRONT. A FEW OF THE MODELS THAT WERE PREVIOUSLY DRY...INCLUDING THE REG GEM AND WRFARW...ARE NOW SHOWING A NARROW BAND OF VERY LIGHT QPF TO MOVE RATHER QUICKLY ACROSS THE AREA BEWTEEN ABOUT 18Z THURSDAY AND 00Z FRIDAY. ONLY MODIFIED POPS UPWARD SLIGHTLY BUT REMAINED IN CHANCE CATEGORY. STILL APPEARS THAT NORTHCENTRAL WISCONSIN WILL HAVE THE GREATEST CHANCE TO SEE SOME VERY LIGHT AND SCATTERED RAIN SHOWER ACTIVITY. AS SYSTEM IS VERY PROGRESSIVE WITH WEAK FORCING...DO NOT EXPECT MORE THAN SOME WIDELY SCATTERED AMOUNTS OF MAYBE A FEW HUNDRETHS OF AN INCH. WILL SEE A GRADUAL INCREASE IN HIGH TO MID-LEVEL CLOUDS THROUGHOUT THE MORNING AS THE SYSTEM APPROACHES. EXPECT MAX TEMPS TO BE GENERALLY SIMILAR TO TODAY WITH READINGS IN THE 40 TO 45 DEGREE RANGE. BOUNDARY LAYER WINDS WILL BE CONSIDERABLY MORE MODEST ON THURSDAY COMPARED TO TODAY AS GRADIENT BAGGIER WITH APPROACHING SURFACE FRONT. .LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY ISSUED AT 251 PM CST WED NOV 13 2013 UPPER LEVEL FLOW SHIFTS DURING THE PERIOD AS A STRONG NORTH-SOUTH UPPER JET MAX...IN EXCESS OF 160 KNOTS...ACROSS THE WEST COAST OF CANADA HELPS TO AMPLIFY A TROUGH IN THE WESTERN CONUS. CONDITIONS SHOULD BE RELATIVELY QUIET THROUGH THE END OF THE WORK WEEK. RAIN IS EXPECTED TO MOVE INTO THE AREA DURING THE WEEKEND AS A SURFACE LOW DEVELOPS IN THE PLAINS...WITH A STRONG FLOW OF WARM AND MOIST AIR AHEAD OF IT. HIGHS WILL BE MUCH ABOVE NORMAL ON SATURDAY AND SUNDAY. THE 12Z GEM AND 12Z GFS HAD THE FIRST OF TWO SURFACE LOWS PASSING THROUGH NORTHWEST WI/NORTHEAST MN SATURDAY NIGHT...WITH A SECOND LOW PASSING THROUGH SOUTHEAST WISCONSIN SOMETIME ON SUNDAY. BOTH OF THESE MODELS SHOWED A PRETTY WIDESPREAD AREA OF QPF OVER THE WEEKEND...WITH THE GFS INDICATING QPF AND MUCH COLDER AIR BEHIND THE SYSTEM. THE 12Z ECMWF HAD A SINGLE...STRONGER SURFACE LOW THAT WAS FORECAST TO PASS ACROSS NORTHWEST WI SUNDAY AFTERNOON AND EVENING. IT ALSO HAD SOME LINGERING PRECIPITATION FORECAST BEHIND THE DEPARTING SYSTEM. RAIN IS LIKELY FOR THE WEEKEND...AND THERE IS A CHANCE OF PRECIPITATION SUNDAY NIGHT AND MONDAY...CHANGING FROM RAIN TO SNOW FROM NORTHWEST TO SOUTHEAST. KEPT A CHANCE FOR SNOW SHOWERS IN THE NORTH LINGERING INTO MONDAY NIGHT. MUCH COLDER TEMPERATURES ARE IN STORE FOR NEXT WEEK WITH SURFACE HIGH PRESSURE OVER THE AREA AND A SHIFT TO NORTHWEST FLOW ALOFT. HIGHS ARE ONLY EXPECTED TO BE AROUND 30 DEGREES FOR THE MIDDLE PART OF THE WEEK. && .AVIATION...FOR 06Z TAF ISSUANCE ISSUED AT 1041 PM CST WED NOV 13 2013 VFR CONDITIONS EXPECTED TO PREVAIL THROUGH AT LEAST THURSDAY MORNING. LLWS SHOULD PERSIST AT RHI UNTIL AROUND 08Z...AUW/CWA AROUND 11Z...AND ATW/GRB UNTIL 14Z. A GRADUAL INCREASE IN MID/HIGH LEVEL CLOUDS IS EXPECTED LATE TONIGHT INTO THURSDAY MORNING AHEAD OF AN APPROACHING WEAK FRONTAL SYSTEM. THIS SYSTEM DOES NOT HAVE MUCH MOISTURE TO WORK WITH...SO MAINLY SPRINKLES ARE EXPECTED DURING THE LATE MORNING AND AFTERNOON. SOME MVFR CIGS MAY DEVELOP BY THURSDAY EVG...AS LOW-LEVEL MOISTURE GRADUALLY INCREASES NEAR THE WEAK FRONTAL BOUNDARY. WILL JUST INCLUDE A TEMPO GROUP TO COVER THIS FOR NOW...AS CONFIDENCE IS NOT HIGH ENOUGH TO CARRY PREVAILING MVFR CONDITIONS. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....ESB LONG TERM......MG AVIATION.......KIECKBUSCH
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
951 PM MST WED NOV 13 2013 .UPDATE... ISSUED AT 829 PM MST WED NOV 13 2013 SURFACE OBSERVATIONS FROM ACROSS THE AREA HAVE YET TO INDICATE ANY PRECIPITATION HITTING THE GROUND...NOT TO SAY SOME LIGHT PRECIPITATION IS NOT OCCURRING IN THE MOUNTAINS. UNR AND CYS RADARS ARE SHOWING A NICE DONUT HOLE AROUND THE RADARS INDICATIVE OF MOISTURE NOT REACHING THE GROUND...BUT RATHER MIDLEVEL CLOUDS AND VIRGA. AT THIS POINT EXPECTING LITTLE IN THE WAY OF PRECIPITATION REACHING THE GROUND TONIGHT. CHANCE FOR MEASURABLE RAIN AND SNOW AT ANY ONE LOCATION IS ON THE LOW SIDE. LATEST 00Z NAM RUN HAS BACKED OFF ON QPF A GREAT DEAL OVER THE 18Z RUN. GFS RUN WILL BE IN SOON AND EXPECTING A SIMILAR RESULT. THE HRRR IS PRODUCING LITTLE IN THE WAY OF PRECIPITATION TONIGHT AS WELL. IR SATELLITE IS ALSO LESS THAN IMPRESSIVE WITH CLOUD TOP WARMING IF ANYTHING. BACKED OFF ON POPS TONIGHT BUT WAS NOT QUITE CONFIDENT ENOUGH TO PULL POPS OUT COMPLETELY AT THIS POINT. EITHER WAY LITTLE TO NO MEASURABLE PRECIPITATION OUTSIDE OF THE MOUNTAINS...AND EVEN THE MOUNTAINS MAY STRUGGLE TO PICK UP MUCH PRECIPITATION TONIGHT. UPDATE ISSUED AT 551 PM MST WED NOV 13 2013 CURRENTLY WATCHING OBSERVATIONS SITES FROM AROUND THE AREA FOR ANY SIGNS OF SNOW REACHING THE GROUND. NAM AND GFS HAVE BIG DIFFERENCES IN THEIR QPF FIELDS THIS EVENING. NAM PRODUCES 3 TENTHS OF AN INCH OF LIQUID OVER NORTHERN CONVERSE COUNTY WHICH WOULD BE EQUIVALENT TO 3 TO 5 INCHES OF SNOW. THE GFS DOES NOT PRODUCE MUCH MORE THAN A DUSTING OF SNOW. BASED ON OBSERVATIONS UPSTREAM THE GFS SEEMS TO HAVE A BETTER HANDLE AT THIS TIME. EXPECTING A FEW INCHES OF SNOW IN THE NORTHERN LARAMIE RANGE WITH AN INCH OR SO INTO THE SNOWY RANGE...OTHERWISE SHOULD NOT SEE MUCH SNOW OUTSIDE OF THE MOUNTAINS WITH THIS QUICK MOVING SYSTEM...BUT WILL BE KEEP A CLOSE EYE ON RADAR THIS EVENING. && .SHORT TERM...(TONIGHT THROUGH FRIDAY) ISSUED AT 308 PM MST WED NOV 13 2013 A SHORTWAVE TROUGH WAS LOCATED FROM NORTHEAST MONTANA TO SOUTHEAST IDAHO EARLY THIS AFTERNOON. CLOUDS HAVE INCREASED OVER THE CWA IN ADVANCE OF THE FEATURE AND ISOLATED SHOWERS WERE CURRENTLY LOCATED OVER THE NORTH AND WEST PARTS OF THE CWA. THE ASSOCIATED SURFACE COLD FRONT EXTENDED FROM SOUTHWEST SOUTH DAKOTA TO SOUTH CENTRAL WYOMING AT 21Z. THE SHORTWAVE TROUGH WILL MOVE QUICKLY EAST AND WILL BE EXITING THE CWA AROUND 12Z. MEANWHILE...THE FRONT WILL MOVE ACROSS THE ENTIRE CWA BY 06Z. SOME SHOWERS WILL OCCUR OVER THE CWA TONIGHT WITH THE NAM DEPICTING MORE QPF THAN THE GFS. WILL INCREASE POPS SOME OVER THE CWA TONIGHT WITH THE PRECIPITATION TYPE SLOWLY MIXING WITH AND CHANGING TO SNOW OVER THE LOWER ELEVATIONS. ONLY A DUSTING OF NEW SNOW IS EXPECTED OVER THE LOWER ELEVATIONS...WITH AN INCH OR SO OVER THE MOUNTAINS. WESTERLY SURFACE WINDS GUSTING TO 35 MPH IN AREAS ALONG AND WEST OF THE LARAMIE RANGE EARLY THIS AFTERNOON WILL SUBSIDE WITH SUNSET AND THE FRONTAL PASSAGE. TEMPERATURES WILL BE COOLER OVER THE CWA ON THURSDAY WITH ONLY THE SNOWY AND SIERRA MADRE RANGES SEEING SOME SNOW SHOWERS. THE NEXT SHORTWAVE TROUGH...CURRENTLY ENTERING CENTRAL BRITISH COLUMBIA WILL MOVE SOUTH AND THE AXIS WILL BE BE NEAR THE WESTERN WYOMING BORDER BY 00Z SATURDAY. MOST OF THE ENERGY WITH THAT FEATURE WILL BE ON THE SOUTHERN PORTION AT THAT TIME...OVER UTAH AND WESTERN COLORADO. THE SOUTHWEST WIND FLOW ALOFT OVER THE CWA AHEAD OF THE SHORTWAVE TROUGH WILL SPREAD CLOUDS OVER THE CWA FRIDAY ALONG WITH SOME SHOWERS OVER AND WEST OF THE LARAMIE RANGE. THE SNOWY AND SIERRA MADRE RANGES SHOULD SEE UP TO AN INCH OF NEW SNOW. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 308 PM MST WED NOV 13 2013 THE SHORTWAVE TROUGH WILL MOVE ACROSS THE ROCKIES FRIDAY NIGHT AND SATURDAY MORNING. MOST OF THE ENERGY STILL REMAINS SOUTH OF THE CWA DURING THAT TIME. HOWEVER...OROGRAPHICS WILL PRODUCE SOME ACCUMULATING SNOW OVER AND NEAR THE MOUNTAINS FRIDAY NIGHT AND SATURDAY MORNING. THE 12Z GFS IS SLOWER THAN THE ECMWF WITH THAT SHORTWAVE TROUGH. THE NEXT SHORTWAVE TROUGH BY 18Z SATURDAY WILL ALREADY BE OVER THE PACIFIC NORTHWEST AND DIGGING. THE TIMING OF THAT FEATURE IS STILL HANDLED DIFFERENTLY BY MODELS. THE ECMWF IS STILL SLOWER THAN THE GFS...BUT IS TRENDING MORE PROGRESSIVE AND TOWARD THE GFS. THE TROUGH AXIS ON BOTH MODELS IS EAST OF THE CWA BY 18Z SUNDAY. COLDER AIR WILL MOVE ACROSS THE CWA BEHIND A SERIES OF COLD FRONTS SATURDAY NIGHT AND EARLY SUNDAY MORNING. BETTER DYNAMICS AND MOISTURE WITH THIS SYSTEM SHOULD PRODUCE A BETTER CHANCE OF SNOW OVER THE CWA SATURDAY NIGHT AND SUNDAY MORNING. THE 300 MB JET WILL BE IN A FAVORABLE POSITION DURING THAT TIME. FOR NOW HAVE BUMPED UP POPS...WITH POSSIBLY SEVERAL INCHES OF SNOW ACCUMULATING OVER THE LOWER ELEVATIONS AND MORE OVER THE MOUNTAINS. COLD TEMPERATURES WILL PERSIST OVER THE CWA ON MONDAY...WITH MODELS PAINTING SOME JET AIDED QPF OVER THE NORTHEAST PART OF THE CWA SUNDAY NIGHT AND MONDAY MORNING. SURFACE HIGH PRESSURE WILL BE OVER THE CWA MONDAY BEFORE MOVING OVER THE PLAINS. HEIGHTS ALOFT REBUILD OVER THE ROCKIES THROUGH AT LEAST TUESDAY WITH A SURFACE TROUGH DEVELOPING OVER THE EAST PART OF THE CWA. WARMER AND DRIER CONDITIONS CAN BE EXPECTED OVER THE CWA FOR TUESDAY. THE NEXT SHORTWAVE TROUGH MOVES ACROSS THE CWA TUESDAY NIGHT AND WEDNESDAY WITH THE ECMWF FASTER THAN THE GFS. A COLD FRONT WILL ALSO MOVE ACROSS THE CWA...BUT AT THIS TIME MODELS ARE NOT SHOWING ANY QPF. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY EVENING) ISSUED AT 943 PM MST WED NOV 13 2013 QUICK MOVING UPPER LEVEL DISTURBANCE AND TRAILING SURFACE COLD FRONT ARE PASSING THROUGH THE FORECAST AREA AT THIS TIME. THERE IS VERY LITTLE MOISTURE ASSOCIATED WITH THIS SYSTEM SO CHANCES FOR PRECIPITATION ARE FEW AND FAR BETWEEN. SOME OF THE HIGHEST MOUNTAIN TOPS MAY BE OBSCURED DO TO MID LEVEL CLOUDS AND SNOW...OTHERWISE MAINLY LOOKING AT VFR TO MVFR CIGS ACROSS THE FORECAST AREA TONIGHT. ANY MVFR CIGS THAT MIGHT DEVELOP TONIGHT WILL ERODE SHORTLY AFTER SUNRISE. && .FIRE WEATHER... ISSUED AT 308 PM MST WED NOV 13 2013 FIRE WEATHER CONCERNS WILL BE MINIMAL OVER THE CWA THROUGH EARLY NEXT WEEK. AFTER A MILD...DRY AND BREEZY DAY TODAY...A SERIES OF COLD FRONTS WILL MOVE ACROSS THE CWA TONIGHT THROUGH SUNDAY. EACH FRONT WILL BRING COOLER AIR WITH A CHANCE OF PRECIPITATION. THE PRECIPITATION WILL BE MAINLY IN THE FORM OF SNOW AND WILL BE MOST LIKELY SATURDAY NIGHT AND SUNDAY MORNING. THE LARGER ACCUMULATIONS OF SNOW WILL OCCUR OVER THE MOUNTAINS. WARMER AND DRIER CONDITIONS WILL RETURN TO THE REGION TUESDAY AND WEDNESDAY. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ UPDATE...LIEBL SHORT TERM...WEILAND LONG TERM...WEILAND AVIATION...LIEBL FIRE WEATHER...WEILAND
AREA FORECAST DISCUSSION...UPDATED
NWS TOPEKA KS
1136 PM CST Fri Nov 15 2013 ...Update to aviation forecast discussion... .SHORT TERM...(This Evening through Saturday) Issued at 250 PM CST FRI NOV 15 2013 On Friday afternoon, an upper trough was located over southern California and Nevada while a series of weaker lead short wave troughs were moving through fairly fast west southwest flow aloft from the four counters into the western Plains. At the surface, low pressure was deepening in eastern Colorado with intensifying pressure gradient and southerly flow from southern Texas through the Dakotas. A pool of quality low level moisture was in place across northeast Texas and moving into eastern Oklahoma. As the lee surface low continues to deepen overnight, expect a strong low level jet to transport this moisture into eastern Kansas with a west to east gradient while a strong elevated mixed layer and warm advection builds above the moist boundary layer. The moist advection will likely occur after a fairly quick evening cool down owing to mostly clear skies, and the influx of moisture into cooler air along with fairly strong ascent overnight and dry air aloft may contribute to periods of drizzle during the early morning hours. There are also some indications of moistening around 10 thousand feet which may lead to weak elevated instability and at least some potential for a few showers given the magnitude of lift. Winds at the surface will also increase through the night as the pressure gradient strengthens. Any light shower activity and drizzle will likely come to an end by late Saturday morning as boundary layer mixing increases and elevated capping increases. As mixing increases, the low level jet will begin to mix gusts to the surface. The LLJ is forecast to have 50+ kt winds at 2500 feet AGL which would easily translate 45+ mph wind gusts to the surface on a clear day, but the stratus deck may be sufficient to limit overall mixing a bit, and by the time clearing is forecast to occur, the LLJ will have weakened a bit. The main question today is whether the depth of mixing will matter given the strength of winds even 1500 feet AGL and the very strong late morning pressure gradient. For now, have not issued a wind advisory, but could certainly see the need to do so if future model guidance suggests the 12Z NAM and recent RAP runs that highlight an even stronger low level wind field. It`s a low confidence wind forecast at this time that could result in peak gusts somewhere between 40 mph and 55 mph, with the strongest winds focused in east central KS. By late afternoon, another lead short wave will approach the area. At least partial afternoon clearing should have occurred with temperatures in the lower 70s and dewpoints in the upper 50s. While a strong capping inversion will be in place for much of the day, it appears that the incoming trough will help cool the cap such that afternoon CINH may decrease into the 10 to 50 J/KG range for a short period between roughly 3 PM and 7 PM before rapidly increasing again. Higher Res model guidance suggests MLCAPE in the 500 to 1000 J/KG range during this period while 0-6 km shear is 40 to 60 kts. While these conditions would normally suggest some potential for a few strong storms, the primary limiting factor...even with the incoming short wave trough...is a general lack of any meaningful surface convergence with the southwesterly low level wind field. The lack of low level forcing along with a lopsided shear/CAPE balance suggests it will be difficult to sustain any updrafts. At this time, will maintain a slight chance of thunderstorms in the eastern parts of KS generally east of Marysville to Burlington, and if one should develop it would warrant an attentive eye. .LONG TERM...(Saturday Night through Friday) Issued at 250 PM CST FRI NOV 15 2013 By Saturday evening as the boundary layer begins to cool the southwesterly low level jet increases which will ultimately strengthen the capping inversion. The increasing low level jet during the evening forces drier air into the lower levels. If an elevated storm is able to form after sunset the dry air intrusion should hinder any persistence. All of these factors should work against any sustained storm threat across the area...therefore went with a dry forecast after 00z Sun. Gusty winds continue for the southeast half of the cwa and especially southeast of the turnpike overnight Saturday into Sunday. Low temperatures range from the mid 40s in north central KS to the mid 50s in east central KS. On Sunday morning the main upper level trough axis passes through the region as well as the associated cold front. The cold front should clear the area by 15z Sun with a significant drop in dew points following the passage. Behind the main trough axis northwesterly flow increases in response to the deepening pressure field across the upper Midwest as the system becomes negatively tilted. Forecast soundings show most locations mixing between 800 to 700 mb especially across central KS where dew points are lower. Red flag criteria is possible Sunday during the day across the western portions of the area with winds gusting to around 35 mph in combination with the low relative humidity. Less certain is the effect cooler air behind the front has on temperatures and how low the dew points get Sunday afternoon determining min RH. Therefore did not issue any headlines and will let later shifts evaluate the latest guidance. High temperatures on Sunday look to reach the upper 50s to low 60s. In the wake of that system dry northwest mid level flow sets up for the central US allowing surface high pressure to build into the region. Winds should begin to decrease Sunday evening with a relatively calm day in store for Monday. The mid level flow quickly transitions to a zonal pattern and return flow develops as the high pressure retreats then the models really start to disagree by mid week. The 12z ECMWF/GEM suggesting precip chances by Wed as a shortwave pushes a front through the region, but this lacks any consistency at this point therefore kept the forecast dry. Although the better chances for precip appear to be on Thurs and Fri as a trough approaches from the west coast. The evolution of that system and the associated surface features is unknown. Have added the possibility of snow Thurs night and Friday which is advertised by the 12z ECMWF but confidence is pretty low. Through the extended temperatures remain near average with highs in the 50s and lows in the 30s with a cooling trend late in the period. && .AVIATION...(For the 06Z TAFs through 06Z Saturday Night) Issued at 1128 PM CST FRI NOV 15 2013 Stratus now developing over eastern OK should spread/develop northward into the Taf sites in the 08Z-11z time frame with mvfr cigs (IFR at KFOE) as gusty south winds continue. Cigs should gradually scatter to vfr aft 14z at KMHK with vfr conditions not working into the KTOP/KFOE until 18z. Also may be some patchy drizzle as well. Otherwise expect most precip to remain south and east of the TAF sites through the fcst...with gusty south/southwest winds of 20-30 gusts to 35kts decreasing aft 23Z. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Barjenbruch LONG TERM...Sanders AVIATION...63
AREA FORECAST DISCUSSION...UPDATED
NWS PITTSBURGH PA
1242 AM EST SAT NOV 16 2013 .SYNOPSIS... A DRY DAY WITH WARMER TEMPERATURES. MORNING CLOUDS WILL GIVE WAY TO SOME SUN IN THE AFTERNOON. A STRONG COLD FRONT WILL BRING WIND AND RAIN TO THE AREA SUNDAY INTO EARLY MONDAY. && .NEAR TERM /THROUGH TODAY/... HAVE UPDATED OVERNIGHT POPS FOR SOUTHERN SHOWERS TO BE MORE IN LINE WITH LATEST GUIDANCE. SHORTWAVE RESPONSIBLE FOR THE SHOWERS IS QUICKLY MOVING INTO CENTRAL PA AND WILL REACH THE EASTERN PART OF THE STATE AROUND 07Z. WITH SHORTWAVE GONE...SHOWERS EXIT THE AREA FOLLOWED BY A BRIEF DECREASE IN CLOUD COVER. MID-LEVEL MOISTURE TO THE SOUTHEAST...VISIBLE ON THE LATEST SAT PICS...WILL ADVECT NORTHEASTWARD LATE TONIGHT. THIS WILL MEAN ANOTHER INCREASE IN CLOUDS FROM SOUTHWEST TO NORTHEAST. WILL ADJUSTS TEMPS TO LATEST GUIDANCE. MID-LEVEL FLOW INCREASE THIS MORNING AND BACKS TO THE SOUTHWEST. THIS WILL CONTINUE TO PULL THE MOISTURE NORTHWARD INTO THE UPPER OHIO VALLEY...IN ADDITION TO WARMER AIR. STRONG WAA WILL BE IN FULL FORCE BY THIS AFTERNOON AND MID-LEVEL MOISTURE LEVELS WILL DECREASE. MODEL SOUNDINGS ARE DEPICTING THIS WELL SHOWING THE OVERALL ATMOSPHERE DRYING OUT LATE THIS MORNING AND THROUGH THE AFTERNOON. THE COMBINATION OF DECREASING CLOUD COVER AND WAA WILL ALLOW FOR TEMPS TO GO 5 TO 10 DEGREES ABOVE NORMAL. && .SHORT TERM /TONIGHT THROUGH MONDAY/... CLOUDS WILL QUICKLY INCREASE TONIGHT AS ANOTHER SHORTWAVE TROUGH SWINGS THROUGH. THE FIRST WAVE WILL MOISTEN THINGS UP AND THE SECOND WAVE...MOVING THROUGH AROUND DAWN...WILL PROVIDE SHOWERS FOR THE REGION BY SUNDAY MORNING. SUNDAY MORNINGS WAVE WILL EXIT BY EARLY AFTERNOON...WHICH WILL ALLOW FOR A BRIEF BREAK IN THE WIDESPREAD RAINFALL. SURFACE WINDS WILL BECOME GUSTY SUNDAY AFTERNOON AS THE SURFACE PRESSURE GRADIENT TIGHTENS AND THE MIXING LAYER RISES...REACHING THE STRONG WINDS ALOFT. ITS NOT OUT OF THE QUESTION THAT WINDS GUSTS SUNDAY AFTERNOON COULD REACH CLOSE TO 40 MPH. WIDESPREAD SHOWERS QUICKLY RE-ENTER THE AREA LATE SUNDAY AHEAD OF THE MAIN COLD FRONT. IN ADDITION TO THE SHOWERS...GUSTY WINDS WILL CONTINUE. THE CONCERN SUNDAY EVENING/NIGHT WILL BE THE POSSIBILITY FOR DAMAGING WINDS WITH THE FRONTAL PASSAGE. COLD FRONT WILL QUICKLY MOVE THROUGH OHIO SUNDAY EVENING...REACHING WESTERN PA AROUND MIDNIGHT. GUSTY WINDS WILL BE ONGOING AHEAD OF THE FRONT...BUT IT APPEARS THAT THERE WILL BE AN INCREASED THREAT FOR DAMAGING WINDS WITH THE PASSAGE OF THE FRONT. MODELS ARE SHOWING A THIN LINE OF STRONG LOW LEVEL FORCING AND MOISTURE CONVERGENCE RIGHT AHEAD OF THE SURFACE BOUNDARY. 0-1KM SHEAR VALUES WILL BE IN EXCESS OF 50KTS SUNDAY EVENING...PLENTY STRONG ENOUGH TO SUSTAIN ELEVATED CONVECTION. MODEL SOUNDINGS ARE PORTRAYING A DEEP MIXING LAYER DEVELOPING WITH STRONG LAPSE RATES MEANING THE VERY STRONG WINDS ALOFT WILL HAVE NO ROADBLOCKS MIXING DOWN TO THE SURFACE. CONVECTION WOULD NEED TO BE ELEVATED AS CONVECTIVE TEMPS AHEAD OF THE FRONT ARE NEAR 70 DEGREES. THIS SCENARIO COULD PLAY OUT VERY SIMILARLY TO THE WIND EVENT THAT OCCURRED A COUPLE OF WEEKS AGO WHEN A LINE OF SHOWERS DEVELOPED WITH THE FRONT AND PROVIDED A BRIEF PERIOD OF DAMAGING WINDS. THE OTHER PART OF THE STORY THAT NEEDS TO BE CONSIDERED IS THE STRONG PRESSURE RISES BEHIND THE FRONT AND SHOWERS. IT IS POSSIBLE THAT THIS FEATURE COULD PROVIDE A SECOND ROUND OF STRONG WIND GUSTS. THE MIXING LAYER WILL SHRINK...BUT WINDS ALOFT ARE STILL PLENTY STRONG. IF THIS SECOND FEATURE COMES TO FRUITION...IT TOO WOULD BE BRIEF. MONDAY IS NOT SETTING UP AS TOO BAD OF A DAY. ATMOSPHERE IS DRY BEHIND THE FRONT AND THE CAA WILL BE WEAK AND SLOW. TEMPS MONDAY WILL BE MORE SEASONABLE. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... A BRIEF PERIOD OF COLDER AIR AND THE POSSIBILITY FOR SNOW SHOWERS MONDAY NIGHT. HIGH PRESSURE WILL RETURN DRY WEATHER AND PROVIDE MODERATING TEMPERATURES FOR THE REMAINDER OF THE LONG TERM. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... WEAK TROUGH PASSING OVER THE AREA TONIGHT COULD RESULT IN PERIODS OF LIGHT SHOWERS PRIMARILY SOUTH OF PITTSBURGH...BUT OPTED NOT TO INCLUDE IN THE 00Z TAF PACKAGE FOR KMGW OR KZZV AS EXPECT COVERAGE TO BE SCATTERED AND DURATION...IF ANY...BRIEF. VFR CONDS EXPECTED OVERNIGHT...BUT LATEST RUC SOUNDINGS INDICATE THE POTENTIAL FOR MVFR CLOUD COVERAGE BY MORNING BETWEEN 11Z AND 12Z. VFR CONDTIONS THEN EXPECTED AREAWIDE BY LATE MORNING. .OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/... RSTRNS ALG WITH A PD OF LLWS AND GUSTY WNDS ARE EXPD WITH THE APCH AND PASSAGE OF A STG CDFNT SUN AND SUN NGT. RSTRNS WL REMAIN PSBL THRU ERLY TUE AS AN UPR TROF CROSSES THE GT LKS IN NW FLOW. BLDG HIGH PRES RTNS VFR CONDS LT TUE. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS DULUTH MN
308 AM CST SAT NOV 16 2013 .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 308 AM CST SAT NOV 16 2013 A WARM SLY FLOW COVERED THE FA AT 08Z WITH A WEAK AREA OF LOW PRESSURE IN NE ND. A WARM FRONT EXTENDED FROM THE LOW CENTER INTO THE NORTHERN PART OF THE AREA WHILE A COLD FRONT WAS IN THE EASTERN DAKOTAS. A MIX OF MID AND HIGH CLOUDS WERE DRIFTING OVER THE WESTERN GREAT LAKES IN THE WAA AHEAD OF THE LOW. MEANWHILE...UPPER LEVEL RIDGING WAS IN PLACE AS SEEN IN WATER VAPOR IMAGERY. EXPECT THE UPPER RIDGE TO MOVE E OF THE AREA THIS MORNING WHILE A TROF DEEPENS OVER THE LEE OF THE ROCKIES. THIS TROF WILL EJECT A VORT MAX INTO CENTRAL MN REACHING NW WI BY 18Z. BROUGHT IN SOME SMALL POPS BY 16Z AND CONTINUE TO SPREAD THEM INTO MUCH OF THE FA BY 18Z IN RESPONSE. LEFT THE WESTERN EDGE DRY ATTM. LATEST MODELS HAVE BACKED OFF ON THE POSSIBILITY OF THUNDERSTORMS UNTIL ABOUT 21Z IN NW WI AND HAVE ADJUSTED ACCORDINGLY. A RUMBLE OF THUNDER MAY BE HEARD AROUND THE PERIPHERY OF WESTERN LAKE SUPERIOR INTO PINE COUNTY MN. BEST INSTABILITY APPEARS TO BE OVER THE EASTERN WI PORTION OF THE FA AND HAVE AN ISOLD MENTION THERE. POPS WILL GRADUALLY INCREASE THROUGH THE AFTERNOON AS A PARADE OF VORT MAXES LIFT NEWD FROM THE BASE OF THE UPPER TROF THROUGH 00Z SUNDAY. PCPN WILL BE ALL LIQUID DUE TO THE WARM ATMOSPHERE IN PLACE. THE UPPER LEVEL LONG WAVE TROF OVER THE ROCKIES CONTINUES TO DEEPEN TONIGHT. MORE VORT MAXES WILL CONTINUE TO EJECT OUT AND INTO THE WESTERN GREAT LAKES. INTERMITTENT BOUTS OF LIGHT RAIN WILL AFFECT THE FA THROUGH THE NIGHT. THE EXCEPTION WILL BE ALONG THE SOUTHERN EDGE LATE TONIGHT WHEN A DRY WEDGE MOVES NEARBY. HAVE A FOG MENTION BEGINNING LATE TONIGHT AS WELL. THE UPPER TROF FINALLY MOVES OUT OF THE ROCKIES INTO THE MIDWEST SUNDAY AND BECOMES NEGATIVELY TILTED. A SFC LOW BECOMES ORGANIZED AHEAD OF THE TROF AND DEEPENS AS IT MOVES FROM SOUTHERN WI INTO LOWER MI BY 00Z MONDAY. BEHIND THIS LOW...CAA BEGINS OVER THE FA ALLOWING FOR A MIX OF RAIN AND SNOW IN THE IN THE NW CORNER SUNDAY MORNING BEFORE CHANGING TO ALL SNOW IN THE AFTERNOON. ONLY A MINOR ACCUMULATION IS EXPECTED. ALL RAIN IS FORECAST FROM WESTERN LAKE SUPERIOR TO THE BRAINERD LAKES E INTO NW WI AS THE ATMOSPHERE WILL BE SLOW TO COOL. .LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY) ISSUED AT 308 AM CST SAT NOV 16 2013 THE NORTHLAND WILL BE IN THE WAKE OF A PASSING STRONG LOW PRESSURE SYSTEM WHICH WILL BE MOVING FROM EASTERN ONTARIO TO WESTERN QUEBEC. COLD AND GUSTY NW FLOW WILL DEVELOP ACROSS THE NORTHLAND SUNDAY NIGHT. THERE MAY BE LINGERING LIGHT RAIN AND SNOW ACROSS THE NORTHLAND SUNDAY NIGHT AND MONDAY MORNING...ESPECIALLY ALONG AND NEAR THE GOGEBIC RANGE IN IRON COUNTY DUE TO THE LAKE ENHANCED AND LAKE EFFECT SNOW SHOWERS. THE GOGEBIC RANGE COULD SEE UP TO A COUPLE INCHES OF SNOW. SEASONABLE TEMPERATURES IN THE UPPER 20S AND LOW 30S MONDAY ARE EXPECTED MONDAY. THERE SHOULD BE A WARMING TREND FOR THE MIDDLE OF THE WEEK AS SOUTHERLY WINDS DEVELOP AHEAD OF LOW PRESSURE MOVING INTO THE WESTERN AND NORTHERN PLAINS. THE WARMING TREND WILL LIKELY CULMINATE WEDNESDAY WITH HIGHS IN THE UPPER 30S AND LOW 40S. THERE COULD BE SOME LIGHT RAIN AND SNOW WEDNESDAY THROUGH THURSDAY AHEAD AND WITH THE PASSAGE OF A COLD FRONT. TEMPERATURES SHOULD BE NEAR NORMAL FOR THE SECOND HALF OF THE WEEK. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 1143 PM CST FRI NOV 15 2013 AN AREA OF LOW PRESSURE...WAA AND MOISTURE ADVECTION WILL ALL COMBINE TO GRADUALLY LOWER CEILINGS THROUGH THE PERIOD TO MAINLY IFR. THE RAP WAS DOING A DECENT JOB DEPICTING THE MVFR CEILINGS OVER MO/IL...AND BRINGS THEM NORTH LATE TONIGHT INTO SATURDAY MORNING AND A LLJ. THERE MAY BE SOME LOW VFR CEILINGS...3500-5000FT...THAT IMPACT KDLH/KHYR LATE TONIGHT AS WELL. RAIN/DRIZZLE WILL DEVELOP DURING THE DAY SATURDAY ALONG WITH THE LOWERING CEILINGS. THE RAIN WILL BE MOST LIKELY OVER EASTERN AREAS OF THE NORTHLAND. && .PRELIMINARY POINT TEMPS/POPS... DLH 44 40 44 24 / 70 70 50 30 INL 44 36 38 21 / 10 60 60 40 BRD 47 39 43 23 / 60 40 30 10 HYR 46 42 47 27 / 70 60 60 40 ASX 48 43 47 29 / 80 60 60 70 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...NONE. && $$ SHORT TERM...GSF LONG TERM...GROCHOCINSKI AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS DULUTH MN
1230 AM CST SAT NOV 16 2013 .UPDATE... ISSUED AT 1227 AM CST SAT NOV 16 2013 REMOVED THE MENTION OF LIGHT RAIN ALONG THE BORDERLAND AS THE RAIN HAS MOVED INTO CANADA. ALSO REMOVED THE MENTION OF FOG FOR THE OVERNIGHT AS DEWPOINT DEPRESSIONS ARE LARGE AND THE FOG AT CKC HAS DISSIPATED. ALSO REMOVED THE MENTION OF DRIZZLE WITH A LACK OF ANY FORCING NEARBY. && .SHORT TERM...(THIS EVENING THROUGH SATURDAY AFTERNOON) ISSUED AT 345 PM CST FRI NOV 15 2013 MAIN CONCERNS IN THE SHORT TERM ARE FOCUSED AROUND THE POTENTIAL FOR PATCHY FOG AND DRIZZLE TONIGHT AND EARLY SATURDAY MORNING...AND THE RAIN SHOWERS EXPECTED TO DEVELOP TOMORROW MID TO LATE MORNING FROM SOUTH TO NORTH AND PERSIST THROUGH THE AFTERNOON. HAVE ALSO ADDED MENTION OF ISOLATED THUNDERSTORMS OVER PARTS OF NW WISCONSIN IN THE LATE AFTERNOON. DEEP CYCLONIC FLOW IN PLACE ACROSS MUCH OF THE CENTRAL CONUS TODAY WITH A COUPLE SHRT WVS RIDING E/NEWD THROUGH THE NRN ROCKIES AND NRN PLAINS. A SFC LOW IS DEVELOPING ALONG THE FRONT RANGE OF THE ROCKIES AS A WEAK WARM FRONT EXTENDS EWD THROUGH NE INTO IA. THIS FRONT WILL LIFT NWD AND COMBINE WITH MODEST WAA/MOISTURE TRANSPORT FROM THE SOUTH AND A FAST MOVING UPPER S/W TO PRODUCE VERY LIGHT PRECIP ACROSS THE NORTHLAND. ABOVE 600MB THE ATMOSPHERE WILL BECOME NEARLY SATURATED. HOWEVER...A FAIRLY DEEP MID-LVL LAYER WILL REMAIN DRY THROUGH MUCH OF THE NIGHT. AS THE NEAR SFC LAYER COOLS AND SATURATES...AND SOME OF THE MOISTURE WORKS ITS WAY DOWN THROUGH THE COLUMN...PATCH DRIZZLE WILL BE POSSIBLE. AT THIS TIME THE MOST FAVORABLE LOCATION OF PRECIP IS DIFFICULT TO NAIL DOWN...SO BASICALLY HAVE A BROAD AREA OF PATCHY FOG AND DRIZZLE. THE SUSTAINED SOUTH WINDS AROUND 5 TO 10 MPH WILL INHIBIT WIDESPREAD FOG FROM FORMING. HOWEVER...A STRONG INVERSION AND PLENTY OF MOISTURE IN THE LOW LEVELS WILL BOTH SUPPORT FOG FORMATION. THE MAIN AREA OF LOW PRESSURE AT THE SFC WILL EVENTUALLY LIFT TO THE NE INTO THE DAKOTAS AND SWRN MN DURING THE DAY SATURDAY AND DRAW UP AN EVEN RICHER SUPPLY OF WARM MOIST AIR FROM THE SOUTH. THIS AIR MASS WILL ALLOW FOR SLIGHT DESTABILIZATION OVER PARTS OF NW WI LATE SAT AFTERNOON. HAVE ADDED ISOLATED THUNDERSTORMS FOR THIS AREA FOR A FEW HOURS. OTHERWISE...PRECIP WILL BE ALL RAIN WITH AMTS AROUND A QUARTER TO A THIRD OF AN INCH...WITH THE HIGHEST AMOUNTS ACROSS THE ERN HALF OF THE FORECAST AREA. TEMPERATURES WILL REMAIN VERY MILD DURING THE NEXT 24 HOURS...WITH LOWS TONIGHT DROPPING INTO THE MID TO UPPER 30S...AND HIGHS TOMORROW IN THE 40S. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 345 PM CST FRI NOV 15 2013 WIDESPREAD PRECIPITATION WILL CONTINUE INTO SATURDAY NIGHT...BEFORE GRADUALLY DECREASING FROM SOUTHWEST TO NORTHEAST. THIS WILL HAPPEN BEFORE A COMPLEX SURFACE LOW DEVELOPS OVER THE REMAINDER OF THE WEEKEND...WITH PRECIPITATION INCREASING ONCE AGAIN. THE SYSTEM IS FAIRLY COMPLEX...WITH THE LOW PRESSURE SYSTEM BASICALLY EVOLVING INTO A MAJOR SURFACE LOW RIGHT OVER OUR REGION. BY LATE SUNDAY... AN INTENSE SURFACE LOW WILL BE LOCATED OVER THE EASTERN LAKE SUPERIOR REGION. THE LOW WILL STRENGTHEN EVEN FURTHER ON SUNDAY NIGHT AND MONDAY...AS IT LIFTS TO NEAR JAMES BAY BY 12Z MONDAY. THE ECMWF HAS IT DROPPING TO A 975 MB LOW AT THAT TIME. AS THE WEEKEND WEARS ON...WE WILL BE LOOKING AT SWITCH TO ALL SNOW...AND A DRAMATIC INCREASE IN WIND. GALES ARE DISTINCTLY POSSIBLE OVER LAKE SUPERIOR...WITH GUSTY WINDS INLAND AS WELL. DRY HIGH PRESSURE WILL THEN BUILD INTO THE REGION FROM MONDAY INTO WEDNESDAY...WITH TEMPERATURES MODERATING CONSIDERABLY BY MIDWEEK. A WEAK LOW PRESSURE SYSTEM AND UPPER LEVEL SHORTWAVE WILL SET OFF SOME LIGHT PRECIPITATION FROM WEDNESDAY NIGHT INTO THURSDAY. BY FRIDAY...THERE IS MAJOR DISAGREEMENT AMONGST THE OPERATIONAL MODEL SET...WITH THE GFS BRINGING A MAJOR STORM SYSTEM TO THE WESTERN GREAT LAKES. THE ECMWF ON THE OTHER HAND...BRINGS DRY AND QUIET WEATHER. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 1143 PM CST FRI NOV 15 2013 AN AREA OF LOW PRESSURE...WAA AND MOISTURE ADVECTION WILL ALL COMBINE TO GRADUALLY LOWER CEILINGS THROUGH THE PERIOD TO MAINLY IFR. THE RAP WAS DOING A DECENT JOB DEPICTING THE MVFR CEILINGS OVER MO/IL...AND BRINGS THEM NORTH LATE TONIGHT INTO SATURDAY MORNING AND A LLJ. THERE MAY BE SOME LOW VFR CEILINGS...3500-5000FT...THAT IMPACT KDLH/KHYR LATE TONIGHT AS WELL. RAIN/DRIZZLE WILL DEVELOP DURING THE DAY SATURDAY ALONG WITH THE LOWERING CEILINGS. THE RAIN WILL BE MOST LIKELY OVER EASTERN AREAS OF THE NORTHLAND. && .PRELIMINARY POINT TEMPS/POPS... DLH 44 40 43 23 / 60 60 60 40 INL 43 36 38 21 / 30 70 60 40 BRD 47 38 42 23 / 50 30 40 20 HYR 45 43 47 26 / 70 60 70 40 ASX 47 43 47 28 / 70 60 70 60 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...NONE. && $$ UPDATE...GSF SHORT TERM...BJT LONG TERM...DAP AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS DULUTH MN
1143 PM CST FRI NOV 15 2013 .SHORT TERM...(THIS EVENING THROUGH SATURDAY AFTERNOON) ISSUED AT 345 PM CST FRI NOV 15 2013 MAIN CONCERNS IN THE SHORT TERM ARE FOCUSED AROUND THE POTENTIAL FOR PATCHY FOG AND DRIZZLE TONIGHT AND EARLY SATURDAY MORNING...AND THE RAIN SHOWERS EXPECTED TO DEVELOP TOMORROW MID TO LATE MORNING FROM SOUTH TO NORTH AND PERSIST THROUGH THE AFTERNOON. HAVE ALSO ADDED MENTION OF ISOLATED THUNDERSTORMS OVER PARTS OF NW WISCONSIN IN THE LATE AFTERNOON. DEEP CYCLONIC FLOW IN PLACE ACROSS MUCH OF THE CENTRAL CONUS TODAY WITH A COUPLE SHRT WVS RIDING E/NEWD THROUGH THE NRN ROCKIES AND NRN PLAINS. A SFC LOW IS DEVELOPING ALONG THE FRONT RANGE OF THE ROCKIES AS A WEAK WARM FRONT EXTENDS EWD THROUGH NE INTO IA. THIS FRONT WILL LIFT NWD AND COMBINE WITH MODEST WAA/MOISTURE TRANSPORT FROM THE SOUTH AND A FAST MOVING UPPER S/W TO PRODUCE VERY LIGHT PRECIP ACROSS THE NORTHLAND. ABOVE 600MB THE ATMOSPHERE WILL BECOME NEARLY SATURATED. HOWEVER...A FAIRLY DEEP MID-LVL LAYER WILL REMAIN DRY THROUGH MUCH OF THE NIGHT. AS THE NEAR SFC LAYER COOLS AND SATURATES...AND SOME OF THE MOISTURE WORKS ITS WAY DOWN THROUGH THE COLUMN...PATCH DRIZZLE WILL BE POSSIBLE. AT THIS TIME THE MOST FAVORABLE LOCATION OF PRECIP IS DIFFICULT TO NAIL DOWN...SO BASICALLY HAVE A BROAD AREA OF PATCHY FOG AND DRIZZLE. THE SUSTAINED SOUTH WINDS AROUND 5 TO 10 MPH WILL INHIBIT WIDESPREAD FOG FROM FORMING. HOWEVER...A STRONG INVERSION AND PLENTY OF MOISTURE IN THE LOW LEVELS WILL BOTH SUPPORT FOG FORMATION. THE MAIN AREA OF LOW PRESSURE AT THE SFC WILL EVENTUALLY LIFT TO THE NE INTO THE DAKOTAS AND SWRN MN DURING THE DAY SATURDAY AND DRAW UP AN EVEN RICHER SUPPLY OF WARM MOIST AIR FROM THE SOUTH. THIS AIR MASS WILL ALLOW FOR SLIGHT DESTABILIZATION OVER PARTS OF NW WI LATE SAT AFTERNOON. HAVE ADDED ISOLATED THUNDERSTORMS FOR THIS AREA FOR A FEW HOURS. OTHERWISE...PRECIP WILL BE ALL RAIN WITH AMTS AROUND A QUARTER TO A THIRD OF AN INCH...WITH THE HIGHEST AMOUNTS ACROSS THE ERN HALF OF THE FORECAST AREA. TEMPERATURES WILL REMAIN VERY MILD DURING THE NEXT 24 HOURS...WITH LOWS TONIGHT DROPPING INTO THE MID TO UPPER 30S...AND HIGHS TOMORROW IN THE 40S. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 345 PM CST FRI NOV 15 2013 WIDESPREAD PRECIPITATION WILL CONTINUE INTO SATURDAY NIGHT...BEFORE GRADUALLY DECREASING FROM SOUTHWEST TO NORTHEAST. THIS WILL HAPPEN BEFORE A COMPLEX SURFACE LOW DEVELOPS OVER THE REMAINDER OF THE WEEKEND...WITH PRECIPITATION INCREASING ONCE AGAIN. THE SYSTEM IS FAIRLY COMPLEX...WITH THE LOW PRESSURE SYSTEM BASICALLY EVOLVING INTO A MAJOR SURFACE LOW RIGHT OVER OUR REGION. BY LATE SUNDAY... AN INTENSE SURFACE LOW WILL BE LOCATED OVER THE EASTERN LAKE SUPERIOR REGION. THE LOW WILL STRENGTHEN EVEN FURTHER ON SUNDAY NIGHT AND MONDAY...AS IT LIFTS TO NEAR JAMES BAY BY 12Z MONDAY. THE ECMWF HAS IT DROPPING TO A 975 MB LOW AT THAT TIME. AS THE WEEKEND WEARS ON...WE WILL BE LOOKING AT SWITCH TO ALL SNOW...AND A DRAMATIC INCREASE IN WIND. GALES ARE DISTINCTLY POSSIBLE OVER LAKE SUPERIOR...WITH GUSTY WINDS INLAND AS WELL. DRY HIGH PRESSURE WILL THEN BUILD INTO THE REGION FROM MONDAY INTO WEDNESDAY...WITH TEMPERATURES MODERATING CONSIDERABLY BY MIDWEEK. A WEAK LOW PRESSURE SYSTEM AND UPPER LEVEL SHORTWAVE WILL SET OFF SOME LIGHT PRECIPITATION FROM WEDNESDAY NIGHT INTO THURSDAY. BY FRIDAY...THERE IS MAJOR DISAGREEMENT AMONGST THE OPERATIONAL MODEL SET...WITH THE GFS BRINGING A MAJOR STORM SYSTEM TO THE WESTERN GREAT LAKES. THE ECMWF ON THE OTHER HAND...BRINGS DRY AND QUIET WEATHER. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 1143 PM CST FRI NOV 15 2013 AN AREA OF LOW PRESSURE...WAA AND MOISTURE ADVECTION WILL ALL COMBINE TO GRADUALLY LOWER CEILINGS THROUGH THE PERIOD TO MAINLY IFR. THE RAP WAS DOING A DECENT JOB DEPICTING THE MVFR CEILINGS OVER MO/IL...AND BRINGS THEM NORTH LATE TONIGHT INTO SATURDAY MORNING AND A LLJ. THERE MAY BE SOME LOW VFR CEILINGS...3500-5000FT...THAT IMPACT KDLH/KHYR LATE TONIGHT AS WELL. RAIN/DRIZZLE WILL DEVELOP DURING THE DAY SATURDAY ALONG WITH THE LOWERING CEILINGS. THE RAIN WILL BE MOST LIKELY OVER EASTERN AREAS OF THE NORTHLAND. && .PRELIMINARY POINT TEMPS/POPS... DLH 39 44 40 43 / 10 60 60 60 INL 37 43 36 38 / 30 30 70 60 BRD 38 47 38 42 / 10 50 30 40 HYR 39 45 43 47 / 10 70 60 70 ASX 41 47 43 47 / 10 70 60 70 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...NONE. && $$ SHORT TERM...BJT LONG TERM...DAP AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1226 AM EST SAT NOV 16 2013 .SYNOPSIS... A WARM FRONT AND COASTAL TROUGH WILL BRING SHOWERS OVERNIGHT. ABOVE NORMAL TEMPERATURES ARE EXPECTED THROUGH THE WEEKEND WITH THE RISK FOR SHOWERS INCREASING AGAIN LATE SUNDAY INTO MONDAY AS A COLD FRONT APPROACHES FROM THE WEST. THE FRONT WILL CROSS THE AREA MONDAY AFTERNOON...FOLLOWED BY DRIER AND COOLER CONDITIONS THROUGH MUCH OF NEXT WEEK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 12:30 AM SATURDAY...NO CHANGES TO THE FORECAST WITH THE LATEST UPDATE. PREVIOUS DISCUSSION FOLLOWS: I`VE GOT TO SAY...THIS FORECAST ISN`T WORKING OUT LIKE I HAD HOPED. THE 00Z CHARLESTON SOUNDING SHOWS PRECIPITABLE WATER HAS RISEN TO NEARLY 1.3 INCHES...BUT ALSO SHOWS SEVERAL 3000-5000 FT THICK DRY LAYERS LOCATED RIGHT IN THE ZONE I WOULD EXPECT THE BEST ISENTROPIC LIFT TO BE OCCURRING. THE 00Z NAM INITIALIZED QUITE WELL VERSUS THE CHARLESTON THERMAL/MOISTURE PROFILE AND HAS REALLY TONED DOWN ITS RAINFALL POTENTIAL THROUGH 12Z. THE 18Z GFS WAS FAR TOO WET AND SHOWS TOO MUCH MOISTURE THROUGHOUT THE 700-400 MB LAYER VERSUS THE CHARLESTON SOUNDING. THE LATEST HRRR ALSO IS NOT CAPTURING TRENDS WELL AND IS BEING IGNORED. CHANGES WITH THIS UPDATE INCLUDE CUTTING POPS BACK TO 40-50 PERCENT FOR THE REMAINDER OF THE NIGHT AND SLASHING QPF FORECASTS TO AROUND 0.05 INCHES. WHILE THE LOCATION AND DEGREE OF ISENTROPIC LIFT HAS PROBABLY BEEN WELL-FORECAST BY THE MODELS ALL ALONG...DRY LIFT DOESN`T YIELD RAINFALL. BREAKS HAVE EVEN OPENED IN THE OVERCAST DECK NEAR GEORGETOWN...MYRTLE BEACH AND CONWAY IN THE PAST HOUR. :( AN INVERTED TROUGH JUST OFFSHORE IS THE SURFACE FEATURE WE ARE WATCHING THIS EVENING. IT EXTENDS NORTH FROM A WEAK LOW JUST EAST OF JACKSONVILLE FL. IN THE UPPER LEVELS A SHORTWAVE TROUGH ACROSS THE SOUTHERN AND CENTRAL APPALACHIANS WILL SWEEP OFFSHORE AFTER MIDNIGHT. A PUSH OF WESTERLY MID-LEVEL WINDS BEHIND THIS FEATURE SHOULD HELP NUDGE THE SURFACE TROUGH FARTHER OFFSHORE AS WELL. OUR LOW LEVEL WINDS WILL BECOME QUITE LIGHT AS THE TROUGH SHIFTS OFFSHORE LATE...WITH LITTLE OPPORTUNITY FOR THE CHILLIER AIR IN THE MOUNTAINS TO ADVECT DOWN TOWARD THE COAST. OVERNIGHT LOW TEMPERATURES ARE STILL EXPECTED TO RANGE FROM THE MID 50S ON THE COAST TO AROUND 50 ON THE INTERSTATE 95 CORRIDOR. THIS IS ON THE HIGH END OF MOS GUIDANCE BUT SEEMS REASONABLE GIVEN PREDOMINANTLY CLOUDY SKIES AND NO SUBSTANTIAL COLD ADVECTION EXPECTED THROUGH DAYBREAK. && .SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY NIGHT/... AS OF 3 PM FRIDAY...A COASTAL TROUGH WILL BE PRESENT OFFSHORE ON SAT. THIS TROUGH WILL LIFT N AND THEN DISSIPATE THROUGH SAT NIGHT. EXPECT ANY LIGHT PRECIPITATION TO BE ENDING DURING SAT. INLAND AREAS SHOULD SEE AN END TO THE SHOWERS IN THE MORNING. SHOWERS MAY LINGER ALONG THE COAST INTO THE AFTERNOON...ESPECIALLY ACROSS THE CAPE FEAR COAST IN CLOSEST PROXIMITY TO THE TROUGH. MOISTURE PROFILES AND MODEL SOUNDINGS SHOW A GRADUAL DECREASE IN MOISTURE ON SAT. A PRONOUNCED NEAR SURFACE INVERSION LINGERS INTO SAT MORNING...BUT EVENTUALLY THE LOW-LEVEL MOISTURE DOES SCOUR OUT. THIS SHOULD ALLOW PARTIAL SUNSHINE TO DEVELOP SAT AFTERNOON WITH THE GREATEST CLOUD COVER LIKELY PERSISTING ACROSS THE CAPE FEAR REGION. A DEEPENING AND STRENGTHENING S TO SW FLOW WILL ENVELOP THE AREA SUN AND SUN NIGHT. ANOTHER PRONOUNCED LOW-LEVEL INVERSION IS EXPECTED TO DEVELOP SAT NIGHT AND THIS WILL LINGER INTO SUN MORNING. THIS INVERSION SHOULD ALLOW LOW STRATUS TO DEVELOP AND PERSIST INTO A GOOD PORTION OF SUN MORNING. AT THE SAME TIME...MID AND HIGH LEVEL MOISTURE WILL BE INCREASING AS PRECIPITABLE WATER VALUES CLIMB TO ABOUT AN INCH AND THREE- QUARTERS SUN EVE AND NIGHT. THUS...SUN LOOKS TO BE A RATHER CLOUDY DAY THROUGHOUT. THE COLUMN BECOMES SUFFICIENTLY MOIST IF NOT SATURATED THROUGH A DEEP LAYER SUN NIGHT AND WILL SHOW POPS INCREASING TO LIKELY OVERNIGHT. IT IS POSSIBLE SHOWERS DEVELOP EARLIER ON SUN...BUT MOST OF THE RAINFALL IS EXPECTED SUN NIGHT AND POSSIBLY INTO MON. AT THIS TIME WILL KEEP MENTION OF ONLY SHOWERS. HOWEVER...INCREASING CAPE VALUES WERE NOTED AND SO THERE IS A SMALL CHANCE FOR A RUMBLE OF THUNDER ALTHOUGH AT THIS TIME...FEEL THE RISK WILL BE CONFINED TO OFFSHORE AREAS WHERE BAROCLINICITY WILL BE HIGHEST. TEMPS WILL BE A DEG OR TWO ABOVE NORMAL BY DAY AS DEVELOPING WARM AIR ADVECTION IS MODERATED BY CONSIDERABLE CLOUD COVER...ESPECIALLY ON SUN. THIS WILL PUT HIGH TEMPS MAINLY IN THE LOWER TO PERHAPS MID 70S. LOW TEMPS WILL HOWEVER BE WELL ABOVE NORMAL...IN THE 50S SAT NIGHT AND IN THE 60S SUN NIGHT. THE NORMAL LOW TEMPS FOR MID NOV ARE IN THE MID 40S. && .LONG TERM /MONDAY THROUGH FRIDAY/... AS OF 3 PM FRIDAY...THE MID LEVEL PATTERN WILL CONSIST OF MAINLY A FLAT/ZONAL FLOW BEYOND MONDAY WHEN A WEAKENING TROUGH WILL USHER THROUGH ANOTHER FAST MOVING FRONT. I DID MAINTAIN THE LIKELY POPS WITH THIS FEATURE FOR ALL OF MONDAY...AT LEAST THROUGH 0000 UTC TUESDAY AS THERE REMAINS JUST ENOUGH DISAGREEMENT IN TIMING BETWEEN THE FASTER GFS SOLUTIONS AND SLOWER WPC PREFERRED ECMWF ENSEMBLE MEAN. WEEKEND SHIFTS SHOULD BE ABLE TO FINE TUNE TIMING. BEYOND THIS...HIGH PRESSURE BUILDS IN BUT THE COLD AIR ADVECTION IS DELAYED SOMEWHAT AS 850MB TEMPERATURES DON/T BOTTOM OUT UNTIL WEDNESDAY AFTERNOON. OVERALL TEMPERATURE TRENDS ARE SOMEWHAT BELOW NORMAL WITH WEDNESDAY AND THURSDAY THE COOLEST WARMING A BIT FRIDAY BASICALLY DUE TO AIR MASS MODIFICATION AND THE DEVELOPMENT OF A COASTAL TROUGH. TUESDAY TEMPERATURES ARE RIGHT AROUND NORMAL. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... AS OF 06Z...RADAR IMAGERY INDICATES THE SHOWERS ASSOCIATED WITH A COASTAL TROUGH HAVE REMAINED OFFSHORE TONIGHT. PRIMARILY VFR CIGS PREVAIL ACROSS THE AREA AS THE MODELS SEEM TO HAVE OVER-ESTIMATED THE AVAILABLE MOISTURE FOR PCPN. BASED ON THESE TRENDS...HAVE CUT BACK PCPN IN THE TAFS TO ONLY MENTION VCSH INTO THE MORNING HOURS. CALM TO LIGHT WINDS ARE EXPECTED OVERNIGHT...BUT THE CLOUD COVER SHOULD KEEP VSBYS FROM SIGNIFICANTLY DROPPING. CANNOT RULE OUT SOME MVFR VSBYS/TEMPO IFR CIGS BEFORE DAYBREAK...BUT AGAIN THE POOR PERFORMANCE OF THE MODELS WITH REGARDS TO THE MOISTURE PROFILES LOWERS MY CONFIDENCE. DO NOT ANTICIPATE ANYTHING WORSE THAN MVFR CONDITIONS OVERNIGHT ATTM. EXPECT MAINLY VFR DURING THE DAYTIME WITH E-NE WINDS AROUND 5 KTS. FOG COULD BE AN ISSUE EARLY SUNDAY...BUT ANY VSBY IMPACTS WILL LIKELY OCCUR AFTER THE VALID TAF PERIOD. EXTENDED OUTLOOK...MVFR/IFR FOG POSSIBLE ON SUNDAY MORNING. EXPECT SHOWERS AND PERIODS OF MVFR/IFR EARLY MONDAY WITH A COLD FRONT. STRATUS POSSIBLE ALONG THE COAST ON WEDNESDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 12:30 AM SATURDAY...NO CHANGES TO THE FORECAST WITH THE LATEST UPDATE. PREVIOUS DISCUSSION FOLLOWS: AN INVERTED SURFACE TROUGH EXTENDS SOUTH-TO-NORTH ACROSS THE CAROLINA COASTAL WATERS. ITS EXACT LOCATION IS TOUGH TO PIN DOWN WITH SPARSE OBSERVATIONS...BUT BASED ON WIND DIRECTIONS AT THE BEACHES AND AT THE FRYING PAN SHOALS BUOY PROBABLY LIES 10-15 MILES EAST OF CAPE FEAR AND 40-45 MILES EAST OF MYRTLE BEACH AND GEORGETOWN. THIS TROUGH SHOULD WEAKEN AND SHIFT EAST AND FARTHER OFFSHORE OVERNIGHT AS AN UPPER LEVEL TROUGH PASSES OVERHEAD AFTER MIDNIGHT. WINDS EAST OF THE TROUGH AXIS ARE GENERALLY E-NE IN THE 8-12 KNOT RANGE...WHILE EAST OF THE TROUGH OVER THE OFFSHORE WATERS THEY ARE SOUTHEAST NEAR 15 KNOTS AT THE FRYING PAN SHOALS BUOY WITH GUSTS TO 17 KNOTS. SEAS HAVE BUILT TO 4 FT OFFSHORE AND TO 2.5 FEET AT THE BUOY JUST SOUTH OF CAPE FEAR. SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 3 PM FRIDAY...A COASTAL TROUGH WILL BISECT THE WATERS ON SAT. THIS TROUGH WILL LIFT N OF THE AREA SAT NIGHT AND DISSIPATE. A COLD FRONT WILL APPROACH FROM THE W SUN AND SUN NIGHT. THE APPROACH OF THIS FRONT WILL GRADUALLY TIGHTEN WHAT WILL OTHERWISE BE A SLACK GRADIENT THIS WEEKEND. THE STRONGEST WINDS ARE EXPECTED SUN NIGHT. THE WINDS WILL BE LIGHT ENE TO E SAT. THE DIRECTION WILL VEER TO SE SAT NIGHT AND TO S ON SUN. WINDS WILL EVENTUALLY COME AROUND TO SW MON MORNING. WIND SPEEDS WILL REACH UP TO 15 TO 20 KT SUN NIGHT. SEAS WILL BE 2 TO 3 FT SAT THROUGH SUN AND THEN BUILD TO 4 TO POSSIBLY 5 FT SUN NIGHT. AN 8 TO 10 SECOND SE SWELL WILL BECOME MORE SIGNIFICANT LATE SUN AND SUN NIGHT. LONG TERM /MONDAY THROUGH WEDNESDAY/... AS OF 3 PM FRIDAY...THE MAIN FEATURE FOR THE MARINE COMMUNITY WILL BE THE FRONT THAT MOVES ACROSS THE WATERS EARLY IN THE PERIOD. THE TIMING REMAINS CONFIDENCE CHALLENGED BUT FOR NOW IT LOOKS LIKE A LATE AFTERNOON WIND SHIFT FROM THE SOUTHWEST TO WEST. NOT THE MOST DYNAMIC OF SYSTEMS SO WINDS WILL TAKE SOME TIME...BY TUESDAY MORNING TO REACH MARGINAL SMALL CRAFT CRITERIA WITH A 20-25 KNOT RANGE. WINDS HAVE A GOOD CHANCE TO STAY ELEVATED AS COLD AIR ADVECTION LAGS WELL BEHIND THE FRONT AND WILL PROBABLY HOVER AROUND 20 KNOTS THROUGH THE END OF THE PERIOD. SEAS WILL BUILD WITH THE WINDS FROM INITIAL VALUES OF 2-4 FEET TO 4-7 FEET BY THE END OF THE PERIOD. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...REK AVIATION...BJR
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1245 AM EST SAT NOV 16 2013 .SYNOPSIS... DISTURBANCE ALOFT EXITING OVERNIGHT. WARMING TREND THROUGH THE WEEKEND. STRONG COLD FRONT CROSSES SUNDAY NIGHT. IN FAST FLOW ALOFT...GUSTY SHOWERS LIKELY. TURNING COLDER MONDAY. && .NEAR TERM /THROUGH TODAY/... UPDATE... ENDED THE POPS QUICKER IN THE OVERNIGHT PERIOD PER LOCAL WRF MODELS AND THE HRRR MODEL. RAIN WEST OF THE TUG FORK RIVER IS MORE SCATTERED IN NATURE...AND WILL SEE THIS TREND MOVING INTO THE WEST VIRGINIA COAL FIELDS IN THE NEXT COUPLE OF HOURS. PREVIOUS DISCUSSION... RADAR AND SATELLITE IMAGES INDICATE SHOWERS STRUGGLING TO REACH THE GROUND ACROSS EASTERN KY THIS AFTERNOON. VERY DRY AIR MASS REMAINS IN PLACE PRODUCING VIRGA FOR THE MOST PART. BELIEVE...THE COLUMN WILL CONTINUE TO MOISTEN...MAKING FEW OF THESE LIGHT SHOWERS TO AFFECT THE EASTERN MOUNTAINS LATER THIS EVENING AND TONIGHT. BREEZY FLOW WILL SUBSIDE LATER TONIGHT AND BECOME MORE SOUTHERLY OVERNIGHT. ADDITIONAL LIGHT SHOWERS WILL BE POSSIBLE ACROSS THE SOUTHERN COAL FIELDS OF WV EARLY SATURDAY. KEPT POPS REACHING LIKELY THIS EVENING ACROSS THE SOUTHEAST HALF OF OUR CWA. MINOR CHANGES TO TEMPERATURES NEEDED. && .SHORT TERM /TONIGHT THROUGH MONDAY/... MODELS ARE IN GOOD AGREEMENT ON THE STRONG COLD FRONT THAT RAPIDLY MOVES ACROSS SUNDAY EVENING AND SUNDAY NIGHT. GIVEN THE ASSOCIATED NEGATIVELY TILTED UPPER TROUGH SWINGING UP THROUGH THE GREAT LAKES WITH A DEEPENING SURFACE LOW...THE MODEL TRENDS OF SPEEDING THE FRONT UP EVEN MORE SEEMS REASONABLE. THE CMC IS EVEN FASTER THAN THE OTHER SWEET OF MODELS...WHICH ONE CANNOT RULE OUT...BUT WILL STICK WITH THE VAST MAJORITY OF GUIDANCE WITH THE TIMING. THIS BRINGS THE FRONT TO THE OHIO RIVER SUNDAY EVENING AND EXITING THE MOUNTAINS AFTER MIDNIGHT SUNDAY NIGHT...WELL BEFORE DAWN MONDAY. IN THIS SYNOPTIC SCENARIO...THE LOW LEVEL WINDS WILL BE QUITE STRONG AND GUSTY MAINLY ALONG AND JUST AHEAD OF THE FRONT...WITH MODEL FORECASTS OF 60 TO 65 KNOTS OF SOUTHWEST WINDS AT 850MB PRECEDING THE FRONT. BEING CLOSER TO THE SURFACE LOW...THESE STRONGEST WINDS WITH THIS SYSTEM WILL BE ACROSS THE NORTHWEST THIRD OF THE AREA SUNDAY AFTERNOON AND SUNDAY EVENING. THERE WILL ALSO BE A BAND OF SHOWERS AND A FEW THUNDERSTORMS AS THE FRONT PASSES THROUGH. GIVEN ALL OF THIS...THE BEST CHANCE OF STRONG AND GUSTY WINDS...POSSIBLY DAMAGING WINDS...WILL BE IN THE CONVECTION ALONG AND JUST AHEAD OF THE FRONT AND ESPECIALLY OVER NORTHWEST PORTIONS OF THE AREA. SPC ALSO HAS A SLIGHT RISK OF SEVERE STORMS SNEAKING IN FROM THE WEST SUNDAY EVENING WITH THE FRONT...WITH THE MAIN THREAT BEING DAMAGING WINDS. THIS IS HIGHLIGHTED IN THE HAZARDOUS WEATHER OUTLOOK PRODUCT. AFTER A DRY AND MILD SATURDAY NIGHT...SUNDAY ITSELF WILL FEATURE A LOT OF CLOUDS AND SCATTERED SHOWERS IN THE WARM ADVECTION AND MOIST SOUTHERLY INFLOW WELL AHEAD OF THE FRONT ITSELF. WHILE CLOUDS WILL HELP LIMIT MIXING WITH THE INCREASING LOW LEVEL WINDS...ONE CANNOT RULE OUT AN ISOLATED DAMAGING GUST IN A SHOWER SUNDAY AFTERNOON... ESPECIALLY NORTHWEST PORTIONS OF THE AREA FOR THE REASONS MENTIONED ABOVE. LOOK FOR TEMPS SUNDAY TO BE WELL ABOVE NORMAL...AROUND 70... DESPITE THE CLOUDS. FRONT BLASTS THRU SUNDAY NIGHT WITH WESTERLY WINDS BRINGING IN A NICE DRY SLOT BY MONDAY MORNING. LOOK FOR A DRY AND A MODESTLY COOLER DAY MONDAY AS MOST OF THE COLD ADVECTION REMAINS NORTH OF US. LATER IN THE DAY MONDAY...AS WINDS DO TURN MORE NORTHWESTERLY...LOOK FOR INCREASED COLD ADVECTION AND UPSLOPE TO BRING A LOW CHANCE OF RAIN SHOWERS IN THE NORTHERN WEST VIRGINIA MOUNTAINS. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... GENERALLY QUIET IN THE EXTENDED. SOME SNOW SHOWERS POSSIBLE ACROSS THE NORTHERN ZONES MONDAY NIGHT AS THE UPPER FLOW TURNS NORTHWESTERLY BRIEFLY. MAINLY ZONAL FLOW MID WEEK WITH SOME UPPER RIDGING TAKING HOLD BY WEEKS END. A CHILLY AIRMASS WILL MODIFY TO NEAR NORMAL BY WEEKS END. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... DISTURBANCE ALOFT EXITING AT 06Z SATURDAY. IT HAS LEFT THE LOW LEVELS IN HTS-CRW-BKW ON SOUTH SATURATED. HAVE CEILINGS LOWERING OVER SOUTHERN MOUNTAINS INCLUDING BKW AT TIMES TO AOB 1 THSD FT BKN IN STRATUS THEN LIFTING AFTER 14Z. WILL HOLD LOWLANDS AROUND HTS-CRW WITHOUT THAT LOW CEILING FORMING...THINKING MORE SCATTERED AS HIGHER CLOUDS THIN 06Z TO 12Z. FROM 14Z THROUGH THE DAY...HAVE LOWEST CEILINGS AROUND THE EASTERN SLOPES INCLUDING POCAHONTAS COUNTY AT 1 TO 2 THSD FT BKN...ALSO SOME 2 THSD FT CEILINGS POSSIBLE IN NORTHEAST KENTUCKY AND SOUTHEAST IN THE MOIST 925 MB SOUTHERLY FLOW. IN BETWEEN THOSE AREAS...FOR THE WESTERN SLOPES...INCLUDING CRW-PKB-CKB HAVE CEILINGS HIGHER MOSTLY 3 TO 5 THSD FT BKN. BY 06Z SUNDAY...CEILINGS REMAINING LOW ALONG THE EASTERN SLOPES WITH SOME AOB 1 THSD FT BKN AND VSBY BLO 3 MILES IN FOG ACROSS HIGH TERRAIN. TO THE WEEST...BY 06Z...SHOWERS MAY REACH INTO PORTIONS OF SOUTHEAST OHIO WITH VSBY NEAR 5 MILES. THE LOW LEVEL FLOW WILL START TO INCREASE 00Z TO 06Z SUNDAY. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z SUNDAY... FORECAST CONFIDENCE: MEDIUM. ALTERNATE SCENARIOS: IN SOUTHERN COUNTIES THROUGH 14Z...WITH LOW LEVELS SATURATED FROM PREVIOUS LIGHT RAIN...SOME STRATUS CEILINGS AOB 1 THSD FT COULD FORM IN THE WESTERN LOWLANDS AROUND HTS-CRW. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. DATE SAT 11/16/13 UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17 EST 1HRLY 01 02 03 04 05 06 07 08 09 10 11 12 CRW CONSISTENCY H H H H M M M H M M M H HTS CONSISTENCY H H M M M M M M M M M H BKW CONSISTENCY M M M M M M M L M M M M EKN CONSISTENCY M H H H H H H H M M M H PKB CONSISTENCY H H H H H H H H H M M H CKB CONSISTENCY H H H H H H H H H H H H AFTER 06Z SUNDAY... IFR IN STRATUS POSSIBLE ON THE EASTERN SLOPES OF THE WV MOUNTAINS THROUGH 15Z SUNDAY MORNING...INCLUDING THE GREENBRIER VALLEY. IN STRONG WIND FLOW AREA WIDE...IFR ALSO POSSIBLE IN GUSTY RAIN SHOWERS SUNDAY AFTERNOON AND SUNDAY NIGHT...AHEAD OF...AND ALONG COLD FRONT. EMBEDDED THUNDER POSSIBLE JUST AHEAD OF THE FRONT SUNDAY EVENING. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...KTB/ARJ/JMV/30 NEAR TERM...ARJ/26 SHORT TERM...JMV LONG TERM...30 AVIATION...KTB
AREA FORECAST DISCUSSION
NWS ABERDEEN SD
332 AM CST SAT NOV 16 2013 .SHORT TERM...TODAY THROUGH MONDAY WEAK UPPER LEVEL DISTURBANCE DRIFTING NORTHEAST ACROSS THE AREA EARLY THIS MORNING. WEAK LIFT SLIDING THROUGH AND FOG SATELLITE SHOWING SOME TEXTURE TO THE MID LEVEL DECK MOVING NORTHEAST THROUGH THE CWA. RADAR HAS SOME VERY LIGHT RETURNS WITHIN THE MID LEVEL DECK......MAYBE JUST A COUPLE SPRINKLES. MAIN THING TO WATCH TODAY IS THE SECONDARY WAVE WHICH IS A TAD FURTHER SOUTH...AND ITS EXPECTED DEVELOPMENT OF SHOWERS ACROSS SOUTHEAST SOUTH DAKOTA INTO MINNESOTA. EVEN THIS CLOSE TO EVENT TIME...MODELS STILL HAVING A TOUGH TIME DETERMINING PLACEMENT OF PRECIP AND THE HANDLING OF THE STRATUS DECK WELL TO THE SOUTH. NO SIGN OF STRATUS ANYWHERE NEAR THE CWA...WITH THINGS RIGHT NOW PUSHED WELL SOUTH INTO KANSAS AND MISSOURI. ALTHOUGH...MODELS STILL SUGGESTING SOME DEVELOPMENT SHORTLY AFTER 12Z. VERY LOW CONFIDENCE IN JUST HOW FAST STRATUS MAKES IT INTO SOUTHEAST SOUTH DAKOTA AND THE SOUTHEAST CWA. FOR RIGHT NOW HAVE CONSTRUCTED SKY GRIDS TO SHOW SOME INCREASE IN CLOUDS LATER THIS MORNING. FEEL THERE WILL BE AT LEAST SOME DEVELOPMENT OF STRATUS BY LATER TODAY. REMOVED DRIZZLE FROM THE FORECAST AS SOUNDINGS OVER THE SOUTHEAST CWA JUST DO NOT SUPPORT IT. NO DEEP MOISTURE LAYER DOWN LOW AT ALL. BETTER SIGNAL SHOWS UP CLOSE TO SIOUX FALLS AREA. WILL LEAVE IN 20 POPS ACROSS THE FAR EASTERN CWA TO SORT OF GO ALONG WITH WHAT THE HRRR AND ABR 4KM MODELS ARE SHOWING. AT THIS POINT...NOT REALLY BUYING INTO THE MORE QPF-HAPPY EC AND GFS WHICH HAS PRECIP BACK FURTHER WEST INTO THE JAMES VALLEY WITHIN A STRATUS DECK. ATTENTION THEN TURNS TO THE STRONGER UPPER LEVEL SHORTWAVE ENERGY MOVING ACROSS THE DAKOTAS LATE TONIGHT THROUGH SUNDAY. MODELS CONTINUE TO WARM THE LOWER LEVELS OF THE ATMOSPHERE AND HAVE INCREASED HIGHS ON SUNDAY. NOW IT APPEARS MOST OF TONIGHT WILL BE DRY WITH CHANCES MOVING INTO THE WESTERN CWA BY 12Z SUNDAY. LEFT PRECIP MOSTLY RAIN THOUGH AS THERMAL PROFILES STILL FAIRLY MILD THROUGH THE NIGHT. AROUND 12Z SUNDAY AND SHORTLY AFTER THE COLUMN BEGINS TO COOL ENOUGH TO SUPPORT MAINLY SNOWFALL DURING THE MORNING HOURS...BUT WARMING AGAIN DURING THE AFTERNOON. MODELS HAVING A TOUGH TIME WITH THIS SHORTWAVE ENERGY AS WELL IN REGARDS TO PRECIP PLACEMENT. OVERALL...A FAIRLY LOW CONFIDENCE FORECAST UNFORTUNATELY. BUT HAVING SAID THAT...IT DOES APPEAR THE BEST CHANCE FOR PRECIP IN THE SHORT TERM WILL BE WITH WHATEVER MATERIALIZES WITHIN THE UPPER LEVEL SHORTWAVE ENERGY LATER TONIGHT THROUGH SUNDAY. ALSO NEED TO MENTION THE WINDS ON SUNDAY AS THEY WILL GET RATHER GUSTY WITHIN A TIGHTENING PRESSURE GRADIENT. COULD BE LOOKING AT WIND ADVISORY SPEEDS OVER THE WESTERN CWA ON SUNDAY. WILL CONTINUE TO MONITOR. .LONG TERM...MONDAY NIGHT THROUGH FRIDAY SEEMS THE GLOBAL SPECTRAL MODELS ARE CONTINUING TO HAVE A TOUGH TIME RESOLVING FLOW PATTERN EVOLUTION AND SHORT-WAVE TIMING IN THE FARTHER OUT FORECAST TIME PERIODS. FOR THE PAST COUPLE OF MORNINGS THE GFS AND ECMWF HAVE BEEN HINTING AT THE DEVELOPMENT OF A PERIOD OF SPLIT FLOW IN THE OUT PERIODS. MODELS ARE KNOWN TO HAVE DIFFICULTIES RESOLVING FLOW PATTERN FEATURES IN THE SHORTER RANGE FORECAST PERIODS /CONSIDERABLY LOWER FORECAST CONFIDENCE/ WHEN A SPLIT FLOW PATTERN IS OCCURRING OR IMMINENT...LET ALONE THE LONGER RANGE FORECAST TIME-FRAME. SO IT WOULD BE SAFE TO SAY...FORECASTER CONFIDENCE IN LONGER RANGE SOLUTIONS IS LOWER THAN NORMAL. THE ECMWF STILL HAS A STRONG COLD FRONT WORKING THROUGH THE REGION BY THE MIDDLE OF NEXT WEEK. IT DOES NOT HAVE A BAND OF SNOW WORKING ACROSS THE CWA...THOUGH...FOR WEDNESDAY NIGHT. THAT FEATURE HAS SLOWED BY ABOUT 12 HOURS AND IS FURTHER SOUTH NOW ACROSS NEBRASKA. THE GFS COLD FRONTAL FEATURE STILL SEEMS TO LAG BEHIND THE ECMWF BY ABOUT 12 HOURS...WHILE THE GEM REMAINS APPX 12 HOURS FASTER THAN THE ECMWF. SO...WITH FRONTAL TIMING DIFFERENCES STILL ABOUNDING...AND PRECIPITATION TIMING/PLACEMENT FORECASTS STILL EVOLVING...SEEMS LIKE GOING AS DRY AS POSSIBLE FOR AS MUCH OF THE LONG TERM AS POSSIBLE IS A GOOD MOVE THIS MORNING. AT THIS POINT...THURSDAY STILL LOOKS LIKE THE COLDEST DAY OF THE EXTENDED...ALTHOUGH THAT WILL PROBABLY CHANGE BY TOMORROW MORNING...AS WELL. && .AVIATION... 06Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS VFR CONDITIONS ARE EXPECTED AT ALL TERMINALS THROUGH TONIGHT. HOWEVER THERE IS ONE CAVEAT. SOME NEW SREF MEMBERS CONTINUE TO BRING LOW CIGS/VSBYS NORTH TO NEAR KATY LATE TNT. THEREFORE WILL PUT IN A MENTION OF IFR/MVFR CIGS LATE TNT AND SATURDAY MORNING FOR KATY. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. && $$ SHORT TERM...TMT LONG TERM...DORN AVIATION...TDK WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
402 AM CST SAT NOV 16 2013 .DISCUSSION... PATCHY FOG...LOCALLY DENSE IN A FEW SPOTS...WILL PERSIST THROUGH MID MORNING BEFORE ERODING. DEEP MOISTURE REMAINS IN PLACE. NOT MUCH IN THE WAY OF A LOW LEVEL FOCUS AND UPPER LEVEL SUPPORT BUT THE MOISTURE LEVELS ARE SO HIGH THAT FEEL SOME SHOWERS WILL DEVELOP DURING THE DAY. BOTH THE RAP AND TEXAS TECH WRF SHOW SHOWERS DEVELOPING THIS AFTN SO WILL ADD 20 POPS BACK TO THE FCST. OVERNIGHT LOWS ON SUN MORNING WILL BE UNSEASONABLY WARM AND MINS WILL ONLY FALL INTO THE UPPER 60S. W-SW WINDS JUST OFF THE SURFACE COUPLED WITH THE WARM START SHOULD YIELD MAX TEMPS IN THE MID 80S. RECORD HIGH TEMPERATURES ARE POSSIBLE ON SUNDAY. FCST SOUNDINGS ON SUNDAY SHOW AN ERODING CAP AND PWATS BETWEEN 1.6 AND 1.8 INCHES SO WILL MAINTAIN 20 POPS ON SUNDAY. A COLD FRONT WILL CROSS SE TX ON MONDAY. GFS LOOKS A BIT FAST WITH THIS FEATURE AND PREFER THE SLOWER NAM/ECMWF SOLN. MSTR POOLS AHEAD OF THE BOUNDARY AND SCT SHRA/TSRA WILL BE POSSIBLE ALONG THE COAST AND PARTS OF THE SOUTHERN CWA. AM CARRYING CHC POPS FOR THE COAST ON MONDAY MORNING BUT FEEL THESE MIGHT BE A TAD LOW. MSTR LEVELS NEVER REALLY DROP OFF THIS WEEK AND AN UPPER LEVEL DISTURBANCE COULD BRING MORE SHOWERS ON TUESDAY AFTN. SW FLOW ALOFT ON THURSDAY WILL BRING A DISTURBANCE ACROSS SE TX. THIS FEATURE COUPLED WITH PWATS AROUND 1.6 INCHES SHOULD AGAIN YIELD MORE PRECIP. MSTR ON THE BACKSIDE OF A RETREATING SURFACE RIDGE WILL CONTINUE TO DRAW DEEPER MSTR INTO SE TX THU/FRI. A COLD FRONT WILL CROSS SE TX ON FRI AND RAIN CHANCES WILL CONTINUE. A DEEP UPPER LEVEL LOW WILL REMAIN WEST OF THE REGION THROUGH NEXT WEEKEND. ISENTROPIC UPGLIDE WILL BE MAXIMIZED WITH NNE SFC WINDS BEING OVERRUN BY SW WINDS ALOFT. NEXT WEEKEND LOOKS RAINY AND KIND OF RAW. MAX TEMPS WILL STRUGGLE TO REACH 50 DEGREES IF THE ECMWF VERIFIES. LEANED TOWARD THE ECMWF NEXT FRI-SUN BUT MODELS DIFFER WITH TIMING AND RUN TO RUN CONSISTENCY HAS BEEN POOR. 43 && .CLIMATE... RECORD HIGH TEMPERATURES ARE POSSIBLE ON SUNDAY. RECORDS FOR SUNDAY NOV 17TH ARE THE FOLLOWING: CURRENT RECORDS FORECAST VALUES IAH 84 - 1985 86 CLL 85 - 1921 86 && .MARINE... LONG PERIOD SWELLS WERE OCCURRING AT BUOY 42019. MAY NEED TO UPGRADE TO A SMALL CRAFT ADVISORY IF THESE CONTINUE AND WILL UPDATE IF NEEDED. OTHERWISE...WINDS WILL GRADUALLY DECREASE LATER TODAY AND TONIGHT AS A COLD FRONT MOVES TOWARD THE COAST. THE FRONT IS EXPECTED TO PUSH OFF THE COAST MONDAY MORNING WITH INITIAL POST FRONTAL WINDS OUT OF THE NORTH. THE MODELS ARE CONSISTENT WITH MODERATE TO STRONG NORTHEAST WINDS DEVELOP MONDAY NIGHT AND TUESDAY. AS HIGH PRESSURE MOVES ACROSS THE LOWER MISSISSIPPI VALLEY INTO THE EASTERN SEABOARD...EXPECT SOUTHEAST WINDS TO DEVELOP BY WEDNESDAY. 40 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 81 71 86 61 74 / 20 20 20 10 10 HOUSTON (IAH) 81 72 86 66 77 / 20 20 20 20 20 GALVESTON (GLS) 77 70 78 69 74 / 20 20 20 30 20 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
1131 PM CST FRI NOV 15 2013 .AVIATION... FOR THE 06Z TAFS...PRIMARY CONCERNS REMAIN THE SMALL POTENTIAL FOR SHRA THROUGH 12Z...AND THE WINDS AFTER 12Z. THE THREAT FOR SHRA APPEARS TO BE LIMITED TO JUST KAMA...PRIMARILY BETWEEN 09 AND 11Z. THE EARLIER CONCERNS FOR DOWNBURSTS WITH SHRA AND VIRGA HAVE DECREASED AS AN INVERSION HAS DEVELOPED...AND DEW POINT DEPRESSIONS ARE MUCH SMALLER NOW. THUS...FEW IMPACTS ARE EXPECTED FROM ANY SHOWERS. WINDS STILL EXPECTED TO INCREASE DRAMATICALLY BETWEEN 15 AND 18Z. KAMA AND KDHT SHOULD SEE WIND SPEEDS APPROACH 30G40KT THROUGH LATE AFTERNOON. WILL WAIT ONE MORE TAF ISSUANCE BEFORE DECIDING ON AN AWW AT KAMA...THOUGH AT THIS POINT...IT APPEARS LIKELY TO BE NEEDED. STILL A SMALL THREAT THAT WITH THE STRONGEST WINDS BLOWING DUST COULD REDUCE VISIBILITIES INTO THE MVFR RANGE. OTHERWISE...VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD. JOHNSON && .PREV DISCUSSION... /ISSUED 518 PM CST FRI NOV 15 2013/ AVIATION... FOR THE 00Z TAFS...THE PRIMARY CONCERNS ARE THE POTENTIAL FOR SHRA TONIGHT...AND WINDS TOMORROW. SHRA WILL BE POSSIBLE AFTER 03Z...THOUGH MORE LIKELY AFTER 06Z...ACROSS THE W AND S TX PANHANDLE. COVERAGE WILL BE LIMITED...SO THERE IS NOT ENOUGH CONFIDENCE TO INCLUDE ANYTHING MORE THAN VCSH AT THIS TIME. HOWEVER...IF A SHRA DOES DIRECTLY IMPACT A TERMINAL...GIVEN VERY DRY LOW LEVELS...THERE IS A THREAT FOR DRY DOWNBURSTS LEADING TO GUSTY AND VARIABLE WINDS. TOMORROW...WINDS WILL INCREASE SHORTLY AFTER 15Z...APPROACHING 30G40KT. HOWEVER...THERE IS ONE CONCERN THAT CLOUDS WILL NOT CLEAR OUT IN TIME TO ALLOW MAXIMUM MIXING. EVEN GRANTING THE CLOUDS ARE SLOWER TO CLEAR OUT...AGREE WITH THE PREVIOUS SHIFT THAT A FEW GUSTS NEAR 40KT ARE LIKELY AT KAMA AND KDHT. FOR NOW HOWEVER...WILL NOT ISSUE AN AWW FOR THE WINDS TOMORROW IN CASE AN AWW WILL BE NEEDED THIS EVENING DUE TO THE GUSTY WINDS WITH SHRA. VFR CONDITIONS ARE EXPECTED WITH THE EXCEPTION OF A SMALL THREAT OF DECREASED VISIBILITIES DUE TO BLOWING DUST IN THE STRONGEST WINDS. JOHNSON PREV DISCUSSION... /ISSUED 232 PM CST FRI NOV 15 2013/ DISCUSSION... FORECAST CHALLENGES OVER THE NEXT 24 HOURS INCLUDE CHANCES FOR ANY CONVECTION TONIGHT AND WIND ADVISORY PROSPECTS FOR SATURDAY. AGREE WITH WFO LUBBOCK AS THE HRRR AND EVEN THE RUC SHOWING PRECIP MOVING NORTH AND EAST OUT OF NEW MEXICO THIS EVENING THROUGH TONIGHT ACROSS MAINLY PARTS OF THE TEXAS PANHANDLE. THIS CONVECTION ASSOCIATED WITH A SHORTWAVE LOCATED OVER WESTERN AND SOUTHERN NEW MEXICO AND FORECAST TO LIFT NORTH AND EAST INTO THE SOUTHWEST AND CENTRAL TEXAS PANHANDLE AFTER 00Z AND 03Z SATURDAY. CONFIDENCE NOT HIGH ENOUGH TO MENTION THUNDER...BUT WILL INTRODUCE ISOLATED SHOWERS FOR THE TONIGHT PERIOD. CONSIDERABLE MID AND HIGH LEVEL CLOUDINESS TONIGHT INTO SATURDAY MAY PUT A DAMPER ON MIXING THE STRONGER WINDS ALOFT AFTER 15Z TO 17Z SATURDAY...HOWEVER AGREE THAT WIND ADVISORY CRITERIA MAY BE MET ON THE CAPROCK BY 18Z SATURDAY. CONFIDENCE JUST NOT HIGH ENOUGH ON TIMING AND LOCATION TO ISSUE A WIND ADVISORY AT THIS TIME. FEEL THAT A NARROW WINDOW OF WIND ADVISORY CRITERIA POSSIBLE BETWEEN ABOUT 17Z AND 21Z SATURDAY...WITH WIND SPEEDS GRADUALLY DECREASING THROUGH THE REMAINDER OF THE AFTERNOON. COLD FRONT EXPECTED TO PUSH SOUTH AND WEST THROUGH THE PANHANDLES DURING THE DAY SUNDAY BRINGING COOLER CONDITIONS EARLY NEXT WEEK. MODERATING TEMPERATURES BY THE MIDDLE OF NEXT WEEK BEFORE ANOTHER COLD FRONT MOVES THROUGH THE FORECAST AREA LATE NEXT WEEK. MEDIUM RANGE MODELS INDICATING POSSIBLE PRECIP CHANCES BY THURSDAY NIGHT OR FRIDAY MAINLY ACROSS THE EASTERN SECTIONS OF THE PANHANDLES AS AN UPPER TROUGH APPROACHES FROM THE FOUR CORNERS AND SOUTHERN ROCKIES. WILL HOLD OFF INTRODUCING ANY POPS IN THE THURSDAY TO FRIDAY TIME FRAME...BUT WILL BUMP UP POPS TO AROUND 10 PERCENT OR SO. SCHNEIDER FIRE WEATHER... MARGINAL ELEVATED FIRE WEATHER CONDITIONS WILL PERSIST UNTIL AROUND SUNSET THIS EVENING WITH THE 20 FOOT WIND SPEEDS GRADUALLY SUBSIDING BUT STILL REMAINING IN THE 15 TO 20 MPH RANGE WITH SOME HIGHER GUSTS. 20 FOOT DOWNSLOPING SOUTHWESTERLY WINDS WILL INCREASE AFTER MID TO LATE MORNING TO AROUND 20 TO 30 MPH WITH HIGHER GUSTS AND MINIMUM AFTERNOON HUMIDITIES FALLING TO NEAR 20 PERCENT. ALTHOUGH ONLY MARGINAL FIRE WEATHER CONDITIONS ARE EXPECTED SATURDAY...THE STRONG WINDS ALONE MAY JUSTIFY ISSUING A FIRE DANGER STATEMENT FOR ELEVATED FIRE WEATHER CONDITIONS. ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS ARE NOT EXPECTED SUNDAY THROUGH LATE NEXT WEEK AS EITHER THE MINIMUM AFTERNOON RELATIVE HUMIDITIES REMAIN AT OR ABOVE 20 PERCENT OR THE 20 FOOT WIND SPEEDS REMAIN BELOW 15 TO 20 MPH. SCHNEIDER && .AMA WATCHES/WARNINGS/ADVISORIES... TX...NONE. OK...NONE. && $$ 16/02
AREA FORECAST DISCUSSION
NWS SPOKANE WA
927 PM PST Fri Nov 15 2013 .SYNOPSIS... A strong weather system will spread rain and snow into most of the region tonight and Saturday with accumulating snow in the mountains as well as some northern valley locations. The weather will trend slightly drier on Sunday into early Monday...except near the Canadian border. A much wetter but warmer weather system will move into the area late Monday and continue through Tuesday and Wednesday. && .DISCUSSION... Looking at recent HRRR runs and some other later model guidance felt it appropriate to delay the start of the wind advisory a few hours to 10 PM PST rather than its earlier 7 PM start as the jet is just a bit slow entering the area. /Pelatti && .AVIATION... 06Z TAFs: Low pressure system dragging wet cold front through and leaving a cold conditionally unstable airmass behind allow for a wet and cluttered forecast with nuisance snow levels near elevations of aviation sites. Thus the nuisance snowfall allows for low ceilings and visibilities tonight and into tomorrow. Wind with the cold front could cause nuisance low level wind shear at times as well and allow for some gusty conditions at locations that mix these winds down to the surface. /Pelatti && .PRELIMINARY POINT TEMPS/POPS... Spokane 33 36 27 40 31 42 / 100 60 10 40 40 10 Coeur d`Alene 33 36 25 38 29 41 / 100 90 20 50 50 20 Pullman 33 37 30 40 32 43 / 100 90 10 40 40 30 Lewiston 38 40 34 46 34 47 / 90 80 20 30 30 20 Colville 34 38 21 37 27 41 / 100 60 20 50 60 20 Sandpoint 33 36 24 37 30 40 / 100 100 40 70 70 50 Kellogg 31 33 26 35 27 39 / 100 100 70 50 60 40 Moses Lake 37 45 29 47 32 47 / 40 10 0 10 10 10 Wenatchee 35 43 30 43 33 46 / 10 10 0 10 10 10 Omak 30 40 26 39 30 43 / 20 10 0 30 20 10 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...Winter Weather Advisory until 10 AM PST Saturday for Coeur d`Alene Area. Winter Storm Warning until 4 AM PST Sunday for Central Panhandle Mountains-Northern Panhandle. Winter Weather Advisory until 4 PM PST Saturday for Lewis and Southern Nez Perce Counties. WA...Winter Weather Advisory until 4 PM PST Saturday for Northeast Mountains-Okanogan Highlands. Wind Advisory from 10 PM this evening to 7 AM PST Saturday for Lower Garfield and Asotin Counties-Upper Columbia Basin- Washington Palouse. Winter Weather Advisory until 4 PM PST Saturday for Northeast Blue Mountains. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS MELBOURNE FL
950 AM EST SAT NOV 16 2013 .DISCUSSION... CANOPY OF MID AND HIGH CLOUD COVER CONTINUES TO STREAM ACROSS CENTRAL FLORIDA FROM THE WEST. RUC13 SHOWS AN ELONGATED VORT IN THE 850-700 MB LAYER IN THE EASTERN GULF. HI RES VIS/IR SAT IMAGERY SHOWS A SFC REFLECTION (NICE TWIST TO THE CLOUDS) IN THE EASTERN GULF JUST NW OF NOAA BUOY 42003 WHICH IS MAINTAINING SHOWERS OVER THE EASTERN GULF. ALTHOUGH NOT ANALYZED BY WPC...THERE ALSO APPEARS TO BE TROUGH AXIS EXTENDING NE FROM THIS GULF LOW/WAVE ACROSS CENTRAL FLORIDA AND INTO THE ATLC. WINDS HAVE TURNED LIGHT N/NE BEHIND THIS TROUGH AXIS FROM ORLANDO NORTHWARD WHILE SE WINDS EXIST TO THE SOUTH. NOT A SIGNIFICANT IMPACT EXCEPT TO BOATERS NORTH OF THE CAPE SO UPDATED THE COASTAL MARINE FCST EARLIER. EXPECT A MORE UNIFORM E/NE FLOW TO DEVELOP THIS AFTERNOON AS THE TROUGH AXIS WEAKENS. WEAK UPGLIDE WILL KEEP THE AREA MOSTLY CLOUDY TO CLOUDY WITH ON AND OFF PATCHES OF LIGHT RAIN/SPRINKLES. THERE MAY BE SOME ADDITIONAL BREAKS IN THE CLOUDS LATER IN THE DAY. HIGHS WILL REACH THE UPPER 70S ORLANDO NORTH AND LOWER 80S SOUTH. && .AVIATION... LARGE AREA OF IFR CIGS AND VSBYS EXIST ACROSS NORTH FL AND GA AND HAVE BEEN CREEPING SOUTHWARD. BUT MID AND HIGH LEVEL OVERCAST ACROSS OUR TERMINALS HAS KEPT THE LOW CLOUDS AT BAY. IT IS POSSIBLE SOME LOW CLOUDS MAY REACH DAB/LEE THROUGH 16Z BUT WILL HANDLE WITH AMD IF NECESSARY. OTHERWISE VFR WITH PREVAILING CIGS BKN-OVC100-150 AND LCL BKN040-060 IN LIGHT PRECIP. COULD SEE SOME LOCAL MVFR VSBYS (NEAR 5SM) IN RAIN. THERE MAY BE A BETTE CHANCE FOR IFR/MVFR FOG/MIST AFT 08Z TONIGHT ACROSS THE NORTH (LEE-DAB). && .MARINE... TRICKY WIND FORECAST THIS MORNING AS A WEAK SURFACE TROUGH HAS DROPPED INTO THE AREA. NORTH TO NORTHEAST WINDS UP TO 15 KNOTS JUST NORTH OF THE CAPE AND SOUTH SOUTHEAST WINDS UP TO 15 KNOTS SOUTH OF THE CAPE. THIS TROUGH APPEARS TO BE TRANSITING E/SE SO MUCH OF THE BREVARD COASTAL WATERS MAY SEE A WIND SHIFT OUT OF THE N/NE THIS MORNING. DO NOT THINK IT WILL MAKE IT SOUTH OF SEBASTIAN INLET. THE TREND GOING INTO THE AFTN SHOULD BE FOR THIS TROUGH/BOUNDARY TO DIMINISH AND ALLOW A MORE UNIFORM E/NE FLOW AROUND 10 KNOTS TO DEVELOP ACROSS ALL THE WATERS. WILL MAINTAIN CAUTION HEADLINE FOR THE OFFSHORE WATERS AND NEARSHORE TREASURE COAST. && .PRELIMINARY POINT TEMPS/POPS... DAB 77 68 80 69 / 30 20 10 20 MCO 79 65 84 67 / 40 30 10 20 MLB 79 72 81 69 / 40 20 10 10 VRB 80 72 82 68 / 40 20 10 10 LEE 79 65 83 66 / 30 30 10 20 SFB 79 65 83 67 / 30 20 10 20 ORL 79 66 83 67 / 40 30 10 20 FPR 80 71 82 69 / 40 20 10 10 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. && $$ KELLY
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
920 AM EST SAT NOV 16 2013 .SYNOPSIS... HIGH PRESSURE CENTERED OFF THE MID-ATLANTIC COAST WILL DIRECT AN ONSHORE FLOW INTO THE FORECAST AREA THROUGH SUNDAY. AN APPROACHING COLD FRONT WILL MOVE THROUGH THE AREA MONDAY. COLD HIGH PRESSURE WILL FOLLOW THE FRONT AND DOMINATE THROUGH THE MIDDLE OF NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... PATCHY FOG CONTINUES THIS MORNING MAINLY AROUND THE COLUMBIA METRO AREA...NOT WIDESPREAD AND EXPECT SLOWLY IMPROVING VISIBILITY DURING THE MORNING. THE NAM AND GFS SHOW RISING H5 HEIGHTS TODAY. WEAK ISENTROPIC LIFT SHOULD SUPPORT SOME CLOUDINESS BUT MOISTURE SHOULD REMAIN SHALLOW. ALL OF THE MOS INDICATES POPS LESS THAN 20 PERCENT. WE WILL GET OFF TO A RELATIVELY WARM START AND WITH RISING HEIGHTS EXPECT TEMPERATURES WILL REACH THE UPPER 60S AND LOWER 70S. && .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/... THE MODELS DISPLAY UPPER HEIGHTS BEGINNING TO FALL TONIGHT IN RESPONSE TO A FAST MOVING TROUGH ACROSS THE UPPER MIDWEST AND DEEPENING SURFACE LOW OVER THE GREAT LAKES. A COLD FRONT WILL PUSH EASTWARD ACROSS THE OHIO AND TENNESSEE VALLEYS SUNDAY EVENING AND PUSH THROUGH THE FORECAST AREA EARLY MONDAY. AHEAD OF THE FRONT...A 30- TO 40-KNOT H85 JET WILL PROVIDE ADEQUATE MOISTURE TRANSPORT AS PRECIPITABLE WATER VALUES INCREASE TO NEAR 2 INCHES (OVER 2 STANDARD DEVIATIONS ABOVE NORMAL). WILL CONTINUE TO FORECAST AN INCREASE IN POPS THROUGH THE AFTERNOON SUNDAY PEAKING WITH LIKELY POPS SUNDAY NIGHT. THERE MAY BE ENOUGH INSTABILITY FOR THUNDERSTORMS SUNDAY NIGHT. THE NAM INDICATES SURFACE-BASED LI/S OF 0 TO -2. SHEAR WILL BE HIGH BUT THE SEVERE THREAT APPEARS LIMITED BECAUSE OF A LACK OF SIGNIFICANT INSTABILITY. POPS SHOULD RAPIDLY DECREASE MONDAY BEHIND THE FRONT. TEMPERATURES AHEAD OF THE FRONT SUNDAY WILL AGAIN BE WARM AND WELL ABOVE NORMAL. HIGH PRESSURE WILL BUILD INTO THE AREA WITH NORTHERLY WINDS IN THE WAKE OF THE COLD FRONT OFF THE COAST AS THE UPPER FLOW BECOMES WESTERLY. THE COOLER AIR WILL BE LAGGING WELL BEHIND THE FRONT AND MONDAY WILL LIKELY FEATURE WELL ABOVE NORMAL TEMPERATURES IN THE 70S AFTER A VERY WARM SUNDAY NIGHT WHERE LOW TEMPERATURES ARE EXPECTED TO BE 15 TO 20 DEGREES ABOVE NORMAL BECAUSE OF CLOUDINESS AND MIXING. && .LONG TERM /TUESDAY THROUGH FRIDAY/... WE HAVE REASONABLY HIGH CONFIDENCE IN A DRY AND FAIR WEATHER PATTERN DURING THE MEDIUM-RANGE PERIOD WITH GOOD MODEL AGREEMENT. THE UPPER PATTERN TUESDAY FEATURES A TROUGH PUSHING OFF THE MID- ATLANTIC COAST WITH WEST TO NORTHWESTERLY FLOW OVER THE FORECAST AREA. GENERALLY DRY ZONAL FLOW EXPECTED WEDNESDAY THROUGH FRIDAY. SURFACE HIGH PRESSURE WILL BUILD OVER THE REGION TUESDAY IN THE WAKE OF THE FRONTAL PASSAGE MONDAY. COOL H85 TEMPERATURES WILL SETTLE OVER THE FORECAST AREA THROUGH MIDWEEK AND DESPITE EXPECTED SUNSHINE...EXPECT TEMPERATURES TO REMAIN SLIGHTLY BELOW NORMAL. SHORTWAVE RIDGING DEVELOPS OVER THE SOUTHEAST BY FRIDAY IN RESPONSE TO A SHARPLY DIGGING UPSTREAM TROUGH BUT PERSISTENT NORTHEASTERLY SURFACE FLOW WILL CONTINUE TO LIMIT WARMING. && .AVIATION /14Z SATURDAY THROUGH WEDNESDAY/... LATEST HRRR GUIDANCE SUGGESTING LOW STRATUS AND OR FOG WILL CONTINUE ACROSS THE AREA THROUGH LATE MORNING... IFR/LIFR CONDITIONS EXPECTED TO CONTINUE ACROSS MUCH OF THE FORECAST AREA UNTIL AROUND 15Z-16Z THIS MORNING THEN SLOW IMPROVEMENT. BY 18Z EXPECT VFR ALL TAF SITES WITH A LIGHT EASTERLY WIND. EXTENDED AVIATION OUTLOOK...INCREASING CONFIDENCE IN RESTRICTIONS SUNDAY MORNING INTO MONDAY. A COLD FRONT IS FORECAST TO CROSS THE AREA EARLY MONDAY. BREEZY CONDITIONS POSSIBLE TUESDAY AND WEDNESDAY. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
957 AM CST SAT NOV 16 2013 .DISCUSSION... 815 AM CST FORECAST UPDATED TO ADD DRIZZLE IN THROUGH THIS MORNING. THE LOW-LEVEL MOISTURE SURGE CONTINUES TO RETURN OVER THE AREA. ISENTROPIC ASCENT ON THE RAP ANALYSIS OF 285K AND 290K SURFACES HAS RAPIDLY SATURATED AND LOOKS TO BE THE ROOT OF THIS. EVEN ON THE 12Z ILX RAOB...THE PROFILE WAS VERY SUGGESTIVE OF DRIZZLE. THIS COULD CONTINUE INTO THIS AFTERNOON BASED ON THE EXTENT OF UPSTREAM OBS ACROSS CENTRAL AND SOUTHERN IL. SOUTH WINDS CONTINUE TO BRING WARM AIR ADVECTION SO TEMPERATURES WILL INCH UPWARD. THE CHANCE FOR TRUE SHOWERS AND POSSIBLY SOME STORMS TODAY STILL LOOKS TO ARRIVE WITH A SHORT WAVE ACROSS THE WESTERN FORECAST AREA BY EARLY AFTERNOON AND SPREADING EAST FROM THERE. MTF //PREV DISCUSSION... 333 AM...FORECAST FOCUS REMAINS POTENTIAL SEVERE WEATHER OUTBREAK ACROSS THE SOUTHERN LAKES AND OHIO VALLEY ON SUNDAY. IN THE SHORT TERM...LOW CLOUDS HAVE STREAMED NORTH ACROSS THE AREA SIGNALING THE BEGINNING OF A SURGE OF LOW LEVEL MOISTURE. DEWPOINTS SLOWLY CREEPING INTO THE LOWER 40S EARLY THIS MORNING WILL CONTINUE TO RISE INTO THE LOWER/MID 50S THIS AFTERNOON...UPPER 50S TONIGHT AND LIKELY POOL IN THE LOWER TO PERHAPS MID 60S JUST AHEAD OF THE COLD FRONT SUNDAY MORNING. LOW PRESSURE OVER NEBRASKA WILL LIFT NORTH TO MINNESOTA BY THIS EVENING AND AS IT DOES...AN UPPER LEVEL WAVE WILL MOVE ACROSS THE AREA THIS AFTERNOON INTO THIS EVENING. MUCH OF THE EASTERN HALF OR TWO THIRDS WILL LIKELY REMAIN DRY THIS MORNING WITH PRECIP SPREADING ACROSS THE WESTERN CWA BY LATE MORNING. HAVE INCLUDED JUST A CHANCE OF THUNDERSTORMS WITH THE STRONGER/CONVECTIVE ELEMENTS BUT CONFIDENCE REGARDING HOW WIDESPREAD LIGHTNING/THUNDER WILL BECOME IS SOMEWHAT LOW AND THUNDER COVERAGE MAY NEED TO BE INCREASED BASED ON SHORT TERM TRENDS ONCE PRECIP DEVELOPS/ARRIVES. THIS ACTIVITY SHOULD MOVE NORTHEAST OF THE AREA BY MID/LATE EVENING WITH A POSSIBLE LULL IN ACTIVITY INTO THE EARLY MORNING HOURS. NOT EXPECTING ANY OF THE THUNDERSTORMS DURING THIS FIRST WAVE TO BE SEVERE. SOME COULD PRODUCE STRONG/GUSTY WINDS AS WELL AS HEAVY RAIN. THOUGH STORM MOTION SHOULD BE SUFFICIENTLY FAST TO PREVENT A LONG DURATION HEAVY RAIN IN ANY ONE LOCATION. RAINFALL AMOUNTS WITH THIS WAVE APPEAR TO BE IN THE 0.5 TO 0.75 RANGE. DESPITE MAINLY CLOUDY SKIES TODAY AND THEN PRECIP THIS AFTERNOON...WITH THE NOTED SURGE IN LOW LEVEL MOISTURE...TEMPS WILL CONTINUE TO CLIMB THROUGH THE DAY WITH CURRENT TEMPS ALREADY IN THE LOWER 50S ACROSS SOUTHERN IL. THUS...HIGHS IN THE UPPER 50S TO LOWER 60S LOOK ON TRACK AND MUCH OF THE SOUTHERN THIRD/HALF OF THE CWA MAY NOT SEE PRECIP UNTIL LATE THIS AFTERNOON AND IF ANY BREAKS DEVELOP...THIS WILL AID TEMPS FURTHER. AS PRECIP ENDS THIS EVENING...POSSIBLE FOR SOME LOCATIONS...ESPECIALLY NORTHERN CWA...TO CONTINUE TO WARM WITH HIGHS BEING REACHED IN THE EVENING. A SECOND LOW THEN DEVELOPS OVER EASTERN COLORADO TONIGHT AND QUICKLY SHIFTS EAST TO IOWA BY SUNDAY MORNING...THEN RAPIDLY DEEPENS AS IT ABSORBS THE FIRST LOW OVER MINNESOTA...AND REACHES LAKE SUPERIOR BY SUNDAY EVENING. A STRONG COLD FRONT WILL RACE ACROSS THE CWA FROM MID/LATE SUNDAY MORNING THROUGH EARLY/MID SUNDAY AFTERNOON. ANOTHER WAVE OF THUNDERSTORMS IS POSSIBLE IN THE EARLY MORNING HOURS OF SUNDAY AHEAD OF THIS SECOND LOW... DEVELOPING OVER EASTERN IOWA AND NORTHWEST IL THEN MOVING INTO SOUTHERN WI...MOSTLY LIKELY BY SUNRISE. AT THE SAME TIME... ADDITIONAL THUNDERSTORMS COULD BE DEVELOPING AHEAD OF THE COLD FRONT ACROSS PARTS OF IOWA/MISSOURI. ANY OF THESE THUNDERSTORMS OVERNIGHT INTO EARLY SUNDAY MORNING COULD BECOME SEVERE. BUT TO WHAT EXTENT AND HOW WIDESPREAD ANY SEVERE WEATHER WOULD BECOME IS UNCERTAIN. HOWEVER...WITH SUCH WARM/MOIST LOW LEVELS...A DEEPENING SURFACE LOW AND WHAT COULD END UP BEING A WARM FRONTAL BOUNDARY ACROSS THE NORTHERN CWA...THE THREAT OF A TORNADO WITH ANY STRONG STORMS CAN/T BE RULED OUT. ANOTHER BRIEF LULL IS EXPECTED SUNDAY MORNING BEFORE WHAT APPEARS LIKE IT COULD BE THE BEGINNING OF A WIDESPREAD SEVERE WEATHER OUTBREAK DEVELOPS. WINDS THROUGH THE ENTIRE COLUMN REMAIN VERY IMPRESSIVE WITH 50 KNOTS AS LOW AS 900MB SUNDAY MORNING. AS NOTED...WHILE THE WARM/MOIST CONDITIONS WILL HELP/AID STORMS STAYING SURFACE BASED...EXPECT QUITE A BIT OF CLOUD COVER...AND WHILE HAVE TRIED TO SHOW SOME PARTLY/MOSTLY CLOUDY CONDITIONS AT LEAST ACROSS THE SOUTHEAST CWA SUNDAY MORNING...ITS POSSIBLE OVERCAST CONDITIONS WILL PERSIST UNTIL FROPA. ADDITIONAL UNCERTAINTY REMAINS WITH WHERE/WHEN THUNDERSTORMS WILL DEVELOP... JUST WEST OF THE CWA...OVER THE CWA...EASTERN CWA/NORTHWEST INDIANA. ENTIRE CWA IS NOW INCLUDED IN SLIGHT RISK PER THIS MORNING/S SPC DAY2 OUTLOOK WITH MODERATE RISK EAST OF THE I-55/I-57 CORRIDOR. POTENTIAL IS CERTAINLY HIGHER OVER THE EASTERN CWA BUT EVEN FROM THIS DISTANCE WILL BE INCLUDING SEVERE MENTION/DAMAGING WINDS IN THE ZONES/GRIDS. THUNDERSTORMS WILL BE ENDING FROM WEST TO EAST DURING THE MID/LATE AFTERNOON AND ALSO ATTEMPTED TO INCLUDE THIS TIMING IN THE GRIDS. THE THREAT OF A TORNADO OR TWO WILL REMAIN SUNDAY BUT DAMAGING WINDS APPEAR TO BE THE PRIMARY SEVERE WEATHER THREAT. DESPITE PRECIPITABLE WATER VALUES ONLY AROUND AN INCH...EXPECT VERY EFFICIENT RAIN PRODUCTION WITH ANOTHER 0.5-0.75 INCHES POSSIBLE...ALTHOUGH PERHAPS MORE LOCALIZED DEPENDING ON CONVECTIVE COVERAGE. STRONG WINDS FROM THE SOUTH WILL DEVELOP TODAY WITH GUSTS INTO THE 30-35 MPH RANGE POSSIBLE. STILL APPEARS THERE COULD BE A 3-6 HOUR WINDOW THIS EVENING OF GUSTS 40+ MPH BEFORE WINDS DIMINISH SOME OVERNIGHT...WHILE CLOSE TO WIND ADVISORY CRITERIA...NOT SURE IT WILL BE REACHED AND NO HEADLINES THROUGH TONIGHT. BY SUNDAY... LOW LEVEL WINDS ARE WELL INTO ADVISORY CRITERIA AND SOME OF THIS WILL LIKELY MIX TO THE SURFACE ESPECIALLY JUST BEHIND THE STORMS/ COLD FRONT AS COLD ADVECTION IS AIDED BY LARGE PRESSURE RISES. THIS IS THIRD PERIOD AND A BIT EARLY FOR AN ADVISORY AND LATER SHIFTS WILL NEED TO ASSESS WIND POTENTIAL/HEADLINES FOR SUNDAY. HAVE CONTINUED INCREASING HIGH TEMPS FOR SUNDAY WITH MID 60S NORTH TO UPPER 60S FROM I-55 SOUTH AND ITS QUITE POSSIBLE SOME AREAS MAY SEE TEMPS TAG 70 AHEAD OF THE FRONT...ESPECIALLY WITH ANY BREAKS IN THE OVERCAST AS 850MB TEMPS ARE NOW EXPECTED TO BE IN THE +12C TO +15C RANGE. WRAP AROUND SHOWERS WILL BE POSSIBLE SUNDAY EVENING BUT SHOULD BE ENDING FAIRLY QUICKLY WITH CLEARING SKIES OVERNIGHT AS HIGH PRESSURE BUILDS INTO THE REGION MONDAY AFTERNOON/MONDAY NIGHT AND THIS HIGH IS MOVING FASTER THAN PREVIOUS MODELS HAD SUGGESTED. WHILE IT WILL TURN MUCH COLDER MONDAY NIGHT WITH LOWS IN THE 30S... MONDAY MAY END UP BEING MAINLY SUNNY WITH DIMINISHING WINDS IN THE AFTERNOON AND TEMPS REBOUNDING BACK INTO THE MID 40S. STILL WILL FEEL MUCH COLDER COMPARED TO SUNDAY...BUT THE TREND IS SLIGHTLY WARMER. HAVE CONTINUED THE WARMING TREND TUESDAY THROUGH THURSDAY AS WINDS TURN SOUTHERLY SOONER ON THE BACK SIDE OF THE DEPARTING HIGH. ALSO NOW APPEARS THE CHANCE OF SHOWERS WILL ARRIVE SOONER...PERHAPS AS EARLY AS LATE WEDNESDAY BUT CERTAINLY WEDNESDAY NIGHT INTO THURSDAY. WARMING TEMPS DURING THIS PERIOD WITH SOUTHERLY FLOW SHOULD KEEP PRECIP MAINLY LIQUID. A COLD FRONT THEN MOVES SOUTH THURSDAY NIGHT AND FRIDAY WITH THE ECMWF MUCH COLDER THAN THE GFS AND HAVE LOWERED TEMPS A FEW DEGREES DURING THIS TIME PERIOD AND WHILE ITS STILL SEVERAL DAYS AWAY...POTENTIAL FOR SOME FROZEN PRECIP EXISTS LATER FRIDAY/FRIDAY NIGHT...DEPENDING ON SPEED OF FRONT AND END TIME OF PRECIP. CMS && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 16Z... * DRIZZLE AND IFR CONDITIONS THROUGH EARLY AFTERNOON...WITH EVEN A CHANCE OF TEMPORARY LIFR. * MVFR CIGS LIKELY WITH A CHANCE OF IFR CIGS TONIGHT. * SOUTH WINDS INCREASING THROUGH THE MORNING WITH GUSTS 25-30 KT THIS AFTERNOON. SOUTH TO SOUTHWEST WIND GUSTS IN EXCESS OF 30 KT EXPECTED SUNDAY. * SHRA EXPECTED LATE THIS AFTERNOON THROUGH THE EVENING WITH THUNDER POSSIBLE. ADDITIONAL LOWER SHRA/TSRA CHANCES OVERNIGHT WITH AN INCREASING CHANCE AFTER DAYBREAK SUNDAY. * LOW LEVEL WIND SHEAR POSSIBLE AS WINDS NEAR 1500 FT INCREASE TO 50 KT. MTF/MDB //DISCUSSION...UPDATED 14Z... TAFS HAVE BEEN UPDATED TO INCLUDE MORE PESSIMISTIC CONDITIONS THIS MORNING DUE TO DRIZZLE AND IFR VISIBLITIES. IFR CONDITIONS EXIST WELL UPSTREAM ACROSS CENTRAL IL SO MAY NEED TO EXTEND DURATION INTO THE AFTERNOON. THERE HAVE BEEN TEMPORARY LIFR CONDITIONS OBSERVED AT SOME AIRPORTS AND POSSIBLE THIS IS SEEN AT SOME OF THE TAF SITES THROUGH EARLY AFTERNOON. PREV DISCUSSION...UPDATED 12Z... LOW PRESSURE IS ORGANIZING ACROSS THE CENTRAL AND NORTHERN PLAINS AND WILL MOVE NORTHEAST TO LAKE SUPERIOR TONIGHT. INCREASING SOUTHERLY FLOW HAS BROUGHT AN INFLUX OF STRATUS AND SOME MIST TO THE TERMINALS OVERNIGHT. SEVERAL SITES HAD DIPPED TO IFR BUT HAVE BEEN SEEING IMPROVEMENT UPSTREAM OVER THE LAST HOUR OR TWO. EXPECT THE IFR CIGS/VSBY TO IMPROVE WITH A STEADIER MVFR CLOUD DECK BECOMING ESTABLISHED THROUGH THE MORNING...LIKELY IN THE 1000-2000 FT RANGE. MVFR LOOKS TO CONTINUE THROUGH THE NIGHT...THOUGH THERE MAY BE SOME BREAKS AT TIMES LATER TODAY AND TONIGHT BUT CONFIDENCE IN DETAILS IS LOW. WINDS WILL BE INCREASING THROUGH THE MORNING WITH GUSTS BECOMING MORE FREQUENT INTO THE AFTERNOON AS GUSTS SPEEDS PUSH 25 TO 30 KT. AN UPPER LEVEL TROUGH WILL CROSS THE AREA LATE THIS AFTERNOON AND THIS EVENING BRINGING SHOWERS WITH IT AS WELL AS AT LEAST A CHANCE FOR THUNDER. HAVE DECENT CONFIDENCE IN THUNDER OCCURRING THOUGH TI MAY NIT IMPACT EACH TERMINAL DIRECTLY. THERE LOOKS TO BE A LULL IN THE PRECIP LATER THIS EVENING AND EARLY TONIGHT BEFORE CHANCE INCREASE EARLY SUNDAY MORNING AS ANOTHER PUSH OF WARMER AIR STREAMS OVER. CIGS MAY LOWER TO IFR OVERNIGHT BUT WILL JUST HINT AT IT WITH SCT IFR LEVEL CLOUD MENTION FOR NOW. WIND GUSTS SHOULD CONTINUE THROUGH THE EVENING AND MAY EVEN INCREASE. RAIN.THUNDER COVERAGE AND TIMING IS SOMEWHAT UNCERTAIN GOING INTO SUNDAY MORNING BUT CHANCES WILL LIKELY INCREASE UNTIL A COLD FRONT CROSSES THE AREA IN CONJUNCTION WITH A SECOND AND MORE INTENSE LOW PRESSURE AREA MOVING NORTH OF THE AREA. SOUTH TO SOUTHWEST WINDS WILL INCREASE SUNDAY MORNING AND GUSTS IN EXCESS OF 35 KT A GOOD POSSIBILITY...WITH THE DIRECTION TURNING MORE WESTERLY THROUGH THE DAY. MDB //ORD AND MDW CONFIDENCE...UPDATED 16Z... * HIGH CONFIDENCE IN IFR CONDITIONS LATE THIS MORNING WITH AT LEAST TEMPORARY SUB 700 FT CIGS AND <3SM VISIBILITY. LOW CONFIDENCE IN DURATION OF THESE CONDITIONS. * MEDIUM-HIGH CONFIDENCE IN MVFR CIGS CONTINUING THROUGH TONIGHT. LOW CONFIDENCE IN IF THERE WILL BE ANY BREAKS TO VFR. * HIGH CONFIDENCE IN WIND DIRECTION FORECAST AND SPEED TRENDS...MEDIUM CONFIDENCE IN TIMING OF GUST DEVELOPMENT. * HIGH CONFIDENCE IN SHRA ARRIVING LATER TODAY...MEDIUM-HIGH CONFIDENCE IN TIMING. MEDIUM-HIGH CONFIDENCE THAT THERE WILL BE AT LEAST SOME THUNDER IN THE AREA. * MEDIUM CONFIDENCE IN LOW LEVEL WIND SHEAR SATURDAY EVENING BUT SURFACE GUSTS MAY PRECLUDE IT. MTF/MDB //OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z... SUNDAY NIGHT...BREEZY WEST WINDS DIMINISHING LATE. MONDAY THROUGH WEDNESDAY...VFR. THURSDAY AND FRIDAY...SLIGHT CHANCE SHRA DURING THE DAY AND RASN AT NIGHT. MAINLY VFR. MDB && .MARINE... 354 AM CST GALES THROUGH MONDAY AND A POTENTIAL PERIOD OF STORM FORCE WINDS SUNDAY EVENING ARE THE FOCUS OF THIS FORECAST PERIOD. HIGH PRESSURE REMAINS CENTERED OFF THE EAST COAST WITH EFFECTS OF THE HIGH SPREAD BACK INTO THE EASTERN LAKES. LOW PRESSURE IS SPREAD ACROSS THE PLAINS AND UPPER MIDWEST WITH CONSOLIDATION EXPECTED TO OCCUR RESULTING IN A LOW TRACKING NORTHEAST TO WESTERN LAKE SUPERIOR SUNDAY MORNING. THE PRESSURE GRADIENT WILL TIGHTEN AS THIS LOW ORGANIZES ALLOWING SOUTH WINDS TO STEADILY INCREASE ACROSS THE LAKE TODAY. WARMER AIR WILL BE MOVING INTO THE REGION WHICH WILL CREATE SOME DEGREE OF A STABLE LAYER OVER THE LAKE TODAY BUT GALES ARE STILL LIKELY TO DEVELOP THIS AFTERNOON AND CONTINUE THIS EVENING. GALES WILL BE A BIT MORE MARGINAL IN THE IL/IN NEARSHORE WATERS BUT OPTED TO HOIST A GALE WARNING FOR THESE AREAS WITH 30 KT LIKELY AND DECENT POTENTIAL FOR GALE FORCE GUSTS WITH QUITE A BIT OF WIND JUST ABOVE THE SURFACE...WITH BETTER MIXING POSSIBLE THANKS TO AN OFFSHORE COMPONENT AT TIMES. WINDS WILL EASE UP FOR A BRIEF PERIOD LATE TONIGHT AND EARLY SUNDAY MORNING SO SPEEDS MAY FALL BELOW GALE FOR SEVERAL HOURS...BUT WINDS WILL INCREASE AGAIN BY SUNDAY AFTERNOON AS A STRONGER LOW EJECTS NORTHEAST FROM EASTERN COLORADO. THIS LOW WILL RAPIDLY DEEPEN AS IT REACHES WISCONSIN AND THE EASTERN U.P. OF MICHIGAN BY SUNDAY EVENING. MUCH WARMER AIR WILL BE DRAWN NORTHWARD ACROSS THE LAKE BUT THE GRADIENT WILL BE TIGHT ENOUGH TO SUPPORT GALES...EVEN IF MIXING IS VERY SHALLOW OVER THE COLDER LAKE WATER. NEARSHORE AREAS MAY SEE THE STRONGEST WINDS DURING THE DAY SUNDAY AS THE FLOW TURNS SOUTHWESTERLY AND WELL MIXED AIR MOVES OFFSHORE. A FURTHER SHIFT TO WESTERLY WINDS WILL OCCUR AS THE LOW FURTHER DEEPENS AND CONTINUES NORTHEAST DRAGGING A SHARP COLD FRONT ACROSS THE LAKE BY SUNDAY EVENING. WITH THE DEEPENING LOW AND UNSTABLE CONDITIONS DEVELOPING WINDS SHOULD INCREASE TO 45 KT WITH A DECENT POTENTIAL FOR 50 KT STORM FORCE WINDS SUNDAY EVENING AND EARLY SUNDAY NIGHT. HAVE DECIDED TO EXTEND THE GALE WARNING FROM LATE TONIGHT THROUGH MONDAY AFTERNOON AND EXPAND INTO THE NEARSHORE WATERS...WITH AN EARLIER END TIME. WILL NEED TO KEEP AN EYE ON THE DURATION OF ANY LULL PERIOD EARLY SUNDAY WHICH MAY ALLOW FOR A SHORT WINDOW WITHOUT A GALE BUT AT THIS POINT THE WINDOW LOOKS RATHER SHORT...ON THE ORDER OF 6-9 HOURS. STILL DO HAVE SOME UNCERTAINTY ON THE TRACK OF THE LOW...WHETHER IT CROSSES THE NORTHERN PART OF THE LAKE OR REMAINS JUST TO THE WEST AND NORTH. RIGHT NOW PREFER THE WESTERN TRACK WHICH WOULD PROVIDE A CLEANER SOUTHWEST TO WEST SHIFT OF THE WINDS AS OPPOSED THE EASTERLY TRACK WHICH WOULD RESULT IN A BRIEF PERIOD OF NORTHERLY WINDS OVER THE NORTHERN SECTIONS OF THE LAKE. WILL NEED TO KEEP AN EYE ON THIS. OTHERWISE WINDS WILL SLOWLY DIMINISH MONDAY AS HIGH PRESSURE PASSES TO THE SOUTH AND EAST OF THE LAKE. LOW PRESSURE IS THEN EXPECTED TO CROSS THE CANADIAN PRAIRIES TO JAMES BAY DURING THE MIDDLE OF NEXT WEEK BRINGING ANOTHER INCREASE IN SOUTH WINDS WHICH WILL FLIP NORTHWEST WITH A COLD FRONTAL PASSAGE LATER THURSDAY. MDB && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS UNTIL NOON SATURDAY. GALE WARNING...NEARSHORE WATERS UNTIL 4 AM MONDAY. GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565- LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868- LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 3 PM MONDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION...UPDATED
NWS CHICAGO/ROMEOVILLE IL
819 AM CST SAT NOV 16 2013 .DISCUSSION... 815 AM CST FORECAST UPDATED TO ADD DRIZZLE IN THROUGH THIS MORNING. THE LOW-LEVEL MOISTURE SURGE CONTINUES TO RETURN OVER THE AREA. ISENTROPIC ASCENT ON THE RAP ANALYSIS OF 285K AND 290K SURFACES HAS RAPIDLY SATURATED AND LOOKS TO BE THE ROOT OF THIS. EVEN ON THE 12Z ILX RAOB...THE PROFILE WAS VERY SUGGESTIVE OF DRIZZLE. THIS COULD CONTINUE INTO THIS AFTERNOON BASED ON THE EXTENT OF UPSTREAM OBS ACROSS CENTRAL AND SOUTHERN IL. SOUTH WINDS CONTINUE TO BRING WARM AIR ADVECTION SO TEMPERATURES WILL INCH UPWARD. THE CHANCE FOR TRUE SHOWERS AND POSSIBLY SOME STORMS TODAY STILL LOOKS TO ARRIVE WITH A SHORT WAVE ACROSS THE WESTERN FORECAST AREA BY EARLY AFTERNOON AND SPREADING EAST FROM THERE. MTF && .PREV DISCUSSION... 333 AM...FORECAST FOCUS REMAINS POTENTIAL SEVERE WEATHER OUTBREAK ACROSS THE SOUTHERN LAKES AND OHIO VALLEY ON SUNDAY. IN THE SHORT TERM...LOW CLOUDS HAVE STREAMED NORTH ACROSS THE AREA SIGNALING THE BEGINNING OF A SURGE OF LOW LEVEL MOISTURE. DEWPOINTS SLOWLY CREEPING INTO THE LOWER 40S EARLY THIS MORNING WILL CONTINUE TO RISE INTO THE LOWER/MID 50S THIS AFTERNOON...UPPER 50S TONIGHT AND LIKELY POOL IN THE LOWER TO PERHAPS MID 60S JUST AHEAD OF THE COLD FRONT SUNDAY MORNING. LOW PRESSURE OVER NEBRASKA WILL LIFT NORTH TO MINNESOTA BY THIS EVENING AND AS IT DOES...AN UPPER LEVEL WAVE WILL MOVE ACROSS THE AREA THIS AFTERNOON INTO THIS EVENING. MUCH OF THE EASTERN HALF OR TWO THIRDS WILL LIKELY REMAIN DRY THIS MORNING WITH PRECIP SPREADING ACROSS THE WESTERN CWA BY LATE MORNING. HAVE INCLUDED JUST A CHANCE OF THUNDERSTORMS WITH THE STRONGER/CONVECTIVE ELEMENTS BUT CONFIDENCE REGARDING HOW WIDESPREAD LIGHTNING/THUNDER WILL BECOME IS SOMEWHAT LOW AND THUNDER COVERAGE MAY NEED TO BE INCREASED BASED ON SHORT TERM TRENDS ONCE PRECIP DEVELOPS/ARRIVES. THIS ACTIVITY SHOULD MOVE NORTHEAST OF THE AREA BY MID/LATE EVENING WITH A POSSIBLE LULL IN ACTIVITY INTO THE EARLY MORNING HOURS. NOT EXPECTING ANY OF THE THUNDERSTORMS DURING THIS FIRST WAVE TO BE SEVERE. SOME COULD PRODUCE STRONG/GUSTY WINDS AS WELL AS HEAVY RAIN. THOUGH STORM MOTION SHOULD BE SUFFICIENTLY FAST TO PREVENT A LONG DURATION HEAVY RAIN IN ANY ONE LOCATION. RAINFALL AMOUNTS WITH THIS WAVE APPEAR TO BE IN THE 0.5 TO 0.75 RANGE. DESPITE MAINLY CLOUDY SKIES TODAY AND THEN PRECIP THIS AFTERNOON...WITH THE NOTED SURGE IN LOW LEVEL MOISTURE...TEMPS WILL CONTINUE TO CLIMB THROUGH THE DAY WITH CURRENT TEMPS ALREADY IN THE LOWER 50S ACROSS SOUTHERN IL. THUS...HIGHS IN THE UPPER 50S TO LOWER 60S LOOK ON TRACK AND MUCH OF THE SOUTHERN THIRD/HALF OF THE CWA MAY NOT SEE PRECIP UNTIL LATE THIS AFTERNOON AND IF ANY BREAKS DEVELOP...THIS WILL AID TEMPS FURTHER. AS PRECIP ENDS THIS EVENING...POSSIBLE FOR SOME LOCATIONS...ESPECIALLY NORTHERN CWA...TO CONTINUE TO WARM WITH HIGHS BEING REACHED IN THE EVENING. A SECOND LOW THEN DEVELOPS OVER EASTERN COLORADO TONIGHT AND QUICKLY SHIFTS EAST TO IOWA BY SUNDAY MORNING...THEN RAPIDLY DEEPENS AS IT ABSORBS THE FIRST LOW OVER MINNESOTA...AND REACHES LAKE SUPERIOR BY SUNDAY EVENING. A STRONG COLD FRONT WILL RACE ACROSS THE CWA FROM MID/LATE SUNDAY MORNING THROUGH EARLY/MID SUNDAY AFTERNOON. ANOTHER WAVE OF THUNDERSTORMS IS POSSIBLE IN THE EARLY MORNING HOURS OF SUNDAY AHEAD OF THIS SECOND LOW... DEVELOPING OVER EASTERN IOWA AND NORTHWEST IL THEN MOVING INTO SOUTHERN WI...MOSTLY LIKELY BY SUNRISE. AT THE SAME TIME... ADDITIONAL THUNDERSTORMS COULD BE DEVELOPING AHEAD OF THE COLD FRONT ACROSS PARTS OF IOWA/MISSOURI. ANY OF THESE THUNDERSTORMS OVERNIGHT INTO EARLY SUNDAY MORNING COULD BECOME SEVERE. BUT TO WHAT EXTENT AND HOW WIDESPREAD ANY SEVERE WEATHER WOULD BECOME IS UNCERTAIN. HOWEVER...WITH SUCH WARM/MOIST LOW LEVELS...A DEEPENING SURFACE LOW AND WHAT COULD END UP BEING A WARM FRONTAL BOUNDARY ACROSS THE NORTHERN CWA...THE THREAT OF A TORNADO WITH ANY STRONG STORMS CAN/T BE RULED OUT. ANOTHER BRIEF LULL IS EXPECTED SUNDAY MORNING BEFORE WHAT APPEARS LIKE IT COULD BE THE BEGINNING OF A WIDESPREAD SEVERE WEATHER OUTBREAK DEVELOPS. WINDS THROUGH THE ENTIRE COLUMN REMAIN VERY IMPRESSIVE WITH 50 KNOTS AS LOW AS 900MB SUNDAY MORNING. AS NOTED...WHILE THE WARM/MOIST CONDITIONS WILL HELP/AID STORMS STAYING SURFACE BASED...EXPECT QUITE A BIT OF CLOUD COVER...AND WHILE HAVE TRIED TO SHOW SOME PARTLY/MOSTLY CLOUDY CONDITIONS AT LEAST ACROSS THE SOUTHEAST CWA SUNDAY MORNING...ITS POSSIBLE OVERCAST CONDITIONS WILL PERSIST UNTIL FROPA. ADDITIONAL UNCERTAINTY REMAINS WITH WHERE/WHEN THUNDERSTORMS WILL DEVELOP... JUST WEST OF THE CWA...OVER THE CWA...EASTERN CWA/NORTHWEST INDIANA. ENTIRE CWA IS NOW INCLUDED IN SLIGHT RISK PER THIS MORNING/S SPC DAY2 OUTLOOK WITH MODERATE RISK EAST OF THE I-55/I-57 CORRIDOR. POTENTIAL IS CERTAINLY HIGHER OVER THE EASTERN CWA BUT EVEN FROM THIS DISTANCE WILL BE INCLUDING SEVERE MENTION/DAMAGING WINDS IN THE ZONES/GRIDS. THUNDERSTORMS WILL BE ENDING FROM WEST TO EAST DURING THE MID/LATE AFTERNOON AND ALSO ATTEMPTED TO INCLUDE THIS TIMING IN THE GRIDS. THE THREAT OF A TORNADO OR TWO WILL REMAIN SUNDAY BUT DAMAGING WINDS APPEAR TO BE THE PRIMARY SEVERE WEATHER THREAT. DESPITE PRECIPITABLE WATER VALUES ONLY AROUND AN INCH...EXPECT VERY EFFICIENT RAIN PRODUCTION WITH ANOTHER 0.5-0.75 INCHES POSSIBLE...ALTHOUGH PERHAPS MORE LOCALIZED DEPENDING ON CONVECTIVE COVERAGE. STRONG WINDS FROM THE SOUTH WILL DEVELOP TODAY WITH GUSTS INTO THE 30-35 MPH RANGE POSSIBLE. STILL APPEARS THERE COULD BE A 3-6 HOUR WINDOW THIS EVENING OF GUSTS 40+ MPH BEFORE WINDS DIMINISH SOME OVERNIGHT...WHILE CLOSE TO WIND ADVISORY CRITERIA...NOT SURE IT WILL BE REACHED AND NO HEADLINES THROUGH TONIGHT. BY SUNDAY... LOW LEVEL WINDS ARE WELL INTO ADVISORY CRITERIA AND SOME OF THIS WILL LIKELY MIX TO THE SURFACE ESPECIALLY JUST BEHIND THE STORMS/ COLD FRONT AS COLD ADVECTION IS AIDED BY LARGE PRESSURE RISES. THIS IS THIRD PERIOD AND A BIT EARLY FOR AN ADVISORY AND LATER SHIFTS WILL NEED TO ASSESS WIND POTENTIAL/HEADLINES FOR SUNDAY. HAVE CONTINUED INCREASING HIGH TEMPS FOR SUNDAY WITH MID 60S NORTH TO UPPER 60S FROM I-55 SOUTH AND ITS QUITE POSSIBLE SOME AREAS MAY SEE TEMPS TAG 70 AHEAD OF THE FRONT...ESPECIALLY WITH ANY BREAKS IN THE OVERCAST AS 850MB TEMPS ARE NOW EXPECTED TO BE IN THE +12C TO +15C RANGE. WRAP AROUND SHOWERS WILL BE POSSIBLE SUNDAY EVENING BUT SHOULD BE ENDING FAIRLY QUICKLY WITH CLEARING SKIES OVERNIGHT AS HIGH PRESSURE BUILDS INTO THE REGION MONDAY AFTERNOON/MONDAY NIGHT AND THIS HIGH IS MOVING FASTER THAN PREVIOUS MODELS HAD SUGGESTED. WHILE IT WILL TURN MUCH COLDER MONDAY NIGHT WITH LOWS IN THE 30S... MONDAY MAY END UP BEING MAINLY SUNNY WITH DIMINISHING WINDS IN THE AFTERNOON AND TEMPS REBOUNDING BACK INTO THE MID 40S. STILL WILL FEEL MUCH COLDER COMPARED TO SUNDAY...BUT THE TREND IS SLIGHTLY WARMER. HAVE CONTINUED THE WARMING TREND TUESDAY THROUGH THURSDAY AS WINDS TURN SOUTHERLY SOONER ON THE BACK SIDE OF THE DEPARTING HIGH. ALSO NOW APPEARS THE CHANCE OF SHOWERS WILL ARRIVE SOONER...PERHAPS AS EARLY AS LATE WEDNESDAY BUT CERTAINLY WEDNESDAY NIGHT INTO THURSDAY. WARMING TEMPS DURING THIS PERIOD WITH SOUTHERLY FLOW SHOULD KEEP PRECIP MAINLY LIQUID. A COLD FRONT THEN MOVES SOUTH THURSDAY NIGHT AND FRIDAY WITH THE ECMWF MUCH COLDER THAN THE GFS AND HAVE LOWERED TEMPS A FEW DEGREES DURING THIS TIME PERIOD AND WHILE ITS STILL SEVERAL DAYS AWAY...POTENTIAL FOR SOME FROZEN PRECIP EXISTS LATER FRIDAY/FRIDAY NIGHT...DEPENDING ON SPEED OF FRONT AND END TIME OF PRECIP. CMS && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 14Z... * DRIZZLE AND IFR CONDITIONS THIS MORNING...WITH EVEN A CHANCE OF TEMPORARY LIFR. * MVFR CIGS LIKELY WITH A CHANCE OF IFR CIGS TONIGHT. * SOUTH WINDS INCREASING THROUGH THE MORNING WITH GUSTS 25-30 KT THIS AFTERNOON. SOUTH TO SOUTHWEST WIND GUSTS IN EXCESS OF 30 KT EXPECTED SUNDAY. * SHRA EXPECTED LATE THIS AFTERNOON THROUGH THE EVENING WITH THUNDER POSSIBLE. ADDITIONAL LOWER SHRA/TSRA CHANCES OVERNIGHT WITH AN INCREASING CHANCE AFTER DAYBREAK SUNDAY. * LOW LEVEL WIND SHEAR POSSIBLE AS WINDS NEAR 1500 FT INCREASE TO 50 KT. MTF/MDB //DISCUSSION...UPDATED 14Z... TAFS HAVE BEEN UPDATED TO INCLUDE MORE PESSIMISTIC CONDITIONS THIS MORNING DUE TO DRIZZLE AND IFR VISIBLITIES. IFR CONDITIONS EXIST WELL UPSTREAM ACROSS CENTRAL IL SO MAY NEED TO EXTEND DURATION INTO THE AFTERNOON. THERE HAVE BEEN TEMPORARY LIFR CONDITIONS OBSERVED AT SOME AIRPORTS AND POSSIBLE THIS IS SEEN AT SOME OF THE TAF SITES THROUGH EARLY AFTERNOON. PREV DISCUSSION...UPDATED 12Z... LOW PRESSURE IS ORGANIZING ACROSS THE CENTRAL AND NORTHERN PLAINS AND WILL MOVE NORTHEAST TO LAKE SUPERIOR TONIGHT. INCREASING SOUTHERLY FLOW HAS BROUGHT AN INFLUX OF STRATUS AND SOME MIST TO THE TERMINALS OVERNIGHT. SEVERAL SITES HAD DIPPED TO IFR BUT HAVE BEEN SEEING IMPROVEMENT UPSTREAM OVER THE LAST HOUR OR TWO. EXPECT THE IFR CIGS/VSBY TO IMPROVE WITH A STEADIER MVFR CLOUD DECK BECOMING ESTABLISHED THROUGH THE MORNING...LIKELY IN THE 1000-2000 FT RANGE. MVFR LOOKS TO CONTINUE THROUGH THE NIGHT...THOUGH THERE MAY BE SOME BREAKS AT TIMES LATER TODAY AND TONIGHT BUT CONFIDENCE IN DETAILS IS LOW. WINDS WILL BE INCREASING THROUGH THE MORNING WITH GUSTS BECOMING MORE FREQUENT INTO THE AFTERNOON AS GUSTS SPEEDS PUSH 25 TO 30 KT. AN UPPER LEVEL TROUGH WILL CROSS THE AREA LATE THIS AFTERNOON AND THIS EVENING BRINGING SHOWERS WITH IT AS WELL AS AT LEAST A CHANCE FOR THUNDER. HAVE DECENT CONFIDENCE IN THUNDER OCCURRING THOUGH TI MAY NIT IMPACT EACH TERMINAL DIRECTLY. THERE LOOKS TO BE A LULL IN THE PRECIP LATER THIS EVENING AND EARLY TONIGHT BEFORE CHANCE INCREASE EARLY SUNDAY MORNING AS ANOTHER PUSH OF WARMER AIR STREAMS OVER. CIGS MAY LOWER TO IFR OVERNIGHT BUT WILL JUST HINT AT IT WITH SCT IFR LEVEL CLOUD MENTION FOR NOW. WIND GUSTS SHOULD CONTINUE THROUGH THE EVENING AND MAY EVEN INCREASE. RAIN.THUNDER COVERAGE AND TIMING IS SOMEWHAT UNCERTAIN GOING INTO SUNDAY MORNING BUT CHANCES WILL LIKELY INCREASE UNTIL A COLD FRONT CROSSES THE AREA IN CONJUNCTION WITH A SECOND AND MORE INTENSE LOW PRESSURE AREA MOVING NORTH OF THE AREA. SOUTH TO SOUTHWEST WINDS WILL INCREASE SUNDAY MORNING AND GUSTS IN EXCESS OF 35 KT A GOOD POSSIBILITY...WITH THE DIRECTION TURNING MORE WESTERLY THROUGH THE DAY. MDB //ORD AND MDW CONFIDENCE...UPDATED 14Z... * HIGH CONFIDENCE IN IFR CONDITIONS THIS MORNING WITH AT LEAST TEMPORARY SUB 700 FT CIGS AND <3SM VISIBILITY. LOW CONFIDENCE IN DURATION OF THESE CONDITIONS. * MEDIUM-HIGH CONFIDENCE IN MVFR CIGS CONTINUING THROUGH TONIGHT. LOW CONFIDENCE IN IF THERE WILL BE ANY BREAKS TO VFR. * HIGH CONFIDENCE IN WIND DIRECTION FORECAST AND SPEED TRENDS...MEDIUM CONFIDENCE IN TIMING OF GUST DEVELOPMENT. * HIGH CONFIDENCE IN SHRA ARRIVING LATER TODAY...MEDIUM-HIGH CONFIDENCE IN TIMING. MEDIUM-HIGH CONFIDENCE THAT THERE WILL BE AT LEAST SOME THUNDER IN THE AREA. * MEDIUM CONFIDENCE IN LOW LEVEL WIND SHEAR SATURDAY EVENING BUT SURFACE GUSTS MAY PRECLUDE IT. MTF/MDB //OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z... SUNDAY NIGHT...BREEZY WEST WINDS DIMINISHING LATE. MONDAY THROUGH WEDNESDAY...VFR. THURSDAY AND FRIDAY...SLIGHT CHANCE SHRA DURING THE DAY AND RASN AT NIGHT. MAINLY VFR. MDB && .MARINE... 354 AM CST GALES THROUGH MONDAY AND A POTENTIAL PERIOD OF STORM FORCE WINDS SUNDAY EVENING ARE THE FOCUS OF THIS FORECAST PERIOD. HIGH PRESSURE REMAINS CENTERED OFF THE EAST COAST WITH EFFECTS OF THE HIGH SPREAD BACK INTO THE EASTERN LAKES. LOW PRESSURE IS SPREAD ACROSS THE PLAINS AND UPPER MIDWEST WITH CONSOLIDATION EXPECTED TO OCCUR RESULTING IN A LOW TRACKING NORTHEAST TO WESTERN LAKE SUPERIOR SUNDAY MORNING. THE PRESSURE GRADIENT WILL TIGHTEN AS THIS LOW ORGANIZES ALLOWING SOUTH WINDS TO STEADILY INCREASE ACROSS THE LAKE TODAY. WARMER AIR WILL BE MOVING INTO THE REGION WHICH WILL CREATE SOME DEGREE OF A STABLE LAYER OVER THE LAKE TODAY BUT GALES ARE STILL LIKELY TO DEVELOP THIS AFTERNOON AND CONTINUE THIS EVENING. GALES WILL BE A BIT MORE MARGINAL IN THE IL/IN NEARSHORE WATERS BUT OPTED TO HOIST A GALE WARNING FOR THESE AREAS WITH 30 KT LIKELY AND DECENT POTENTIAL FOR GALE FORCE GUSTS WITH QUITE A BIT OF WIND JUST ABOVE THE SURFACE...WITH BETTER MIXING POSSIBLE THANKS TO AN OFFSHORE COMPONENT AT TIMES. WINDS WILL EASE UP FOR A BRIEF PERIOD LATE TONIGHT AND EARLY SUNDAY MORNING SO SPEEDS MAY FALL BELOW GALE FOR SEVERAL HOURS...BUT WINDS WILL INCREASE AGAIN BY SUNDAY AFTERNOON AS A STRONGER LOW EJECTS NORTHEAST FROM EASTERN COLORADO. THIS LOW WILL RAPIDLY DEEPEN AS IT REACHES WISCONSIN AND THE EASTERN U.P. OF MICHIGAN BY SUNDAY EVENING. MUCH WARMER AIR WILL BE DRAWN NORTHWARD ACROSS THE LAKE BUT THE GRADIENT WILL BE TIGHT ENOUGH TO SUPPORT GALES...EVEN IF MIXING IS VERY SHALLOW OVER THE COLDER LAKE WATER. NEARSHORE AREAS MAY SEE THE STRONGEST WINDS DURING THE DAY SUNDAY AS THE FLOW TURNS SOUTHWESTERLY AND WELL MIXED AIR MOVES OFFSHORE. A FURTHER SHIFT TO WESTERLY WINDS WILL OCCUR AS THE LOW FURTHER DEEPENS AND CONTINUES NORTHEAST DRAGGING A SHARP COLD FRONT ACROSS THE LAKE BY SUNDAY EVENING. WITH THE DEEPENING LOW AND UNSTABLE CONDITIONS DEVELOPING WINDS SHOULD INCREASE TO 45 KT WITH A DECENT POTENTIAL FOR 50 KT STORM FORCE WINDS SUNDAY EVENING AND EARLY SUNDAY NIGHT. HAVE DECIDED TO EXTEND THE GALE WARNING FROM LATE TONIGHT THROUGH MONDAY AFTERNOON AND EXPAND INTO THE NEARSHORE WATERS...WITH AN EARLIER END TIME. WILL NEED TO KEEP AN EYE ON THE DURATION OF ANY LULL PERIOD EARLY SUNDAY WHICH MAY ALLOW FOR A SHORT WINDOW WITHOUT A GALE BUT AT THIS POINT THE WINDOW LOOKS RATHER SHORT...ON THE ORDER OF 6-9 HOURS. STILL DO HAVE SOME UNCERTAINTY ON THE TRACK OF THE LOW...WHETHER IT CROSSES THE NORTHERN PART OF THE LAKE OR REMAINS JUST TO THE WEST AND NORTH. RIGHT NOW PREFER THE WESTERN TRACK WHICH WOULD PROVIDE A CLEANER SOUTHWEST TO WEST SHIFT OF THE WINDS AS OPPOSED THE EASTERLY TRACK WHICH WOULD RESULT IN A BRIEF PERIOD OF NORTHERLY WINDS OVER THE NORTHERN SECTIONS OF THE LAKE. WILL NEED TO KEEP AN EYE ON THIS. OTHERWISE WINDS WILL SLOWLY DIMINISH MONDAY AS HIGH PRESSURE PASSES TO THE SOUTH AND EAST OF THE LAKE. LOW PRESSURE IS THEN EXPECTED TO CROSS THE CANADIAN PRAIRIES TO JAMES BAY DURING THE MIDDLE OF NEXT WEEK BRINGING ANOTHER INCREASE IN SOUTH WINDS WHICH WILL FLIP NORTHWEST WITH A COLD FRONTAL PASSAGE LATER THURSDAY. MDB && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS UNTIL NOON SATURDAY. GALE WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745...NOON SATURDAY TO 4 AM MONDAY. GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565- LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868- LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...NOON SATURDAY TO 3 PM MONDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
646 AM EST SAT NOV 16 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 521 AM EST SAT NOV 16 2013 SOUTHWESTERLY FLOW IS BEGINNING TO INCREASE OVER THE CWA AS THE UPPER TROUGH AMPLIFIES DUE TO A STRONG SHORTWAVE MOVING SOUTHEAST THROUGH THE PACIFIC NORTHWEST. THIS SHORTWAVE WILL BE THE MAJOR PLAYER TO OUR WEATHER FOR THE SECOND HALF OF THE WEEKEND. FOR THE SHORT TERM...THE SOUTHWESTERLY FLOW ALOFT WILL ALLOW A SHORTWAVE CURRENTLY LOCATED NEAR THE FOUR CORNERS REGION TO MOVE NORTHEAST ACROSS THE UPPER GREAT LAKES LATE THIS AFTERNOON AND EVENING. MOISTURE STREAMING NORTHEAST ON WV IMAGERY IS LEADING TO SOME HIGH CLOUDS OVER MUCH OF UPPER MICHIGAN. IN THE LOWER LEVELS...INITIAL RAP SOUNDINGS SHOWING PLENTY OF DRY AIR BELOW THE HIGH CLOUDS BUT THERE WAS ENOUGH RADIATIONAL COOLING EARLIER THIS EVENING TO PRODUCE SOME PATCHY FOG OVER CENTRAL/EASTERN UPPER MICHIGAN. THE DRIER LOW LEVELS WILL LIKELY BE SHORT LIVED AS 3-5KFT CEILINGS COVER MUCH OF CENTRAL/NORTHERN WISCONSIN AND WILL BE MOVING INTO THE AREA OVER THE NEXT COUPLE OF HOURS. IN ADDITION TO THOSE CLOUDS...MODELS ARE SHOWING THE DEVELOPING 1KFT CEILINGS IN NORTHERN ILLINOIS TO QUICKLY LIFT NORTH AND EXPAND THIS MORNING AND EARLY AFTERNOON...COVERING MUCH OF UPPER MICHIGAN. THE SHORTWAVE WILL BE NEARING THE REGION THIS AFTERNOON AND THERE ARE SEVERAL FEATURES SUPPORTING A BROAD AREA OF RAIN MOVING THROUGH THE AREA LATE THIS AFTERNOON AND EVENING. FIRST...EXPECT THERE TO BE A WEAK COUPLED JET STRUCTURE OVER THE AREA THIS EVENING. BROAD MID LEVEL WARM AIR ADVECTION AND MOISTURE TRANSPORT WILL ACCOMPANY THIS SHORTWAVE...WITH THE EASTERN CWA SEEING THE BEST OF BOTH FEATURES. AT THE SURFACE...THE BROAD LOW DEVELOPING OVER THE CENTRAL/NORTHERN PLAINS WILL SLIDE A TROUGH THROUGH MINNESOTA TODAY AND OVER WESTERN LAKE SUPERIOR TONIGHT. HAVE HIGH CONFIDENCE IN THE FORECAST FOR THIS AFTERNOON/EVENING BASED OFF GREAT MODEL CONSISTENCY. SINCE THE BEST FORCING IS OVER THE SOUTHEAST HALF...WILL HAVE THE HIGHEST POPS/QPF IN THAT AREA BUT THERE WILL BE A PERIOD OF DEFINITE POPS OVER THE ENTIRE AREA. AS FOR QPF...EXPECT VALUES TO RANGE FROM 0.2 OVER THE WEST TO 0.75IN OVER THE EAST...WITH SOME HIGHER AMOUNTS IF THERE ARE SOME EMBEDDED THUNDERSTORMS. AS FOR THUNDER...THERE IS A POCKET OF 50-125J/KG OF MUCAPE AND SHOWALTER VALUES SLIGHTLY BELOW 0 OVER THE EASTERN 2/3RDS OF THE CWA LATE THIS AFTERNOON INTO THE EVENING HOURS. BOTH 00Z NAM AND 21Z SREF PROBABILITIES INDICATE THE POTENTIAL FOR A RUMBLE OF THUNDER OR TWO OVER THE SOUTHEAST PART OF THE CWA...WHICH CORRELATES WELL WITH POCKET OF STEEPER 850-500MB LAPSE RATES MOVING THROUGH AND BEST FORCING. PREVIOUS SHIFT HAD A SLIGHT CHANCE MENTIONED (WHICH SEEMS REASONABLE) AND ONLY MADE MINOR TWEAKS. ALL OF THE FORCING FEATURES WILL SHIFT NORTHEAST AROUND OR SHORTLY AFTER MIDNIGHT (AND MID LEVEL DRYING OCCURS)...SO HAVE A DIMINISHING TREND TO THE POPS FROM SOUTHWEST TO NORTHEAST. WITH THE DEEP MOISTURE DEPARTING...DID TRANSITION THE PRECIP WORDING FROM RAIN TO DRIZZLE OVERNIGHT (MAINLY OVER THE EASTERN AREAS). MODELS MATCH UP WITH THAT IDEA (BLOTCHY LOOK TO QPF IN THE HIGHER RESOLUTION RUNS). DID CONTINUE TO MENTION SOME FOG WITH THE RAIN THIS EVENING...ALTHOUGH THE WIND MIGHT HELP KEEP IT MORE OF A STRATUS WITH ONLY A SLIGHT LOWERING OF VISIBILITIES EXCEPT OVER THE HIGHER TERRAIN. THUS...HAVE KEPT MOST OF THE AREA UNDER PATCHY WORDING...ALTHOUGH DID IT DIMINISH OVER THE WEST OVERNIGHT AS LOWER LEVEL AIR SLIDES IN. FINALLY...WILL SEE INCREASING SOUTHERLY WINDS TODAY WITH A TIGHTENING PRESSURE GRADIENT BETWEEN THE HIGH OFF THE EAST COAST AND TROUGH MOVING EAST THROUGH MINNESOTA. STRONGEST WINDS WILL BE OVER THE EASTERN CWA...WHERE THE LOW LEVEL JET WILL BE LOCATED. WITH THE INCREASING LOW LEVEL MOISTURE AND EXPECTED CLOUD COVER...THINK THAT WILL LIMIT MIXING AND KEEP WINDS IN CHECK (OCCASIONAL GUSTS IN THE 20-30MPH RANGE SEEN ON BUFKIT MOMENTUM TRANSFER). ABOVE NORMAL TEMPERATURES WILL CONTINUE TODAY AND TONIGHT AS WARM AIR SLIDES NORTH OVER THE AREA. THIS WARM AIR WILL REALLY SURGE IN TONIGHT...WHICH COULD CAUSE MOST LOWS TO OCCUR EARLY THIS EVENING AND THEN RISING OVERNIGHT INTO THE UPPER 40S AND AROUND 50. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 521 AM EST SAT NOV 16 2013 LONG TERM WILL START WITH A STRONG STORM SYSTEM LIFTING THRU THE UPPER GREAT LAKES...BRINGING RAIN AND THEN A TRANSITION TO STRONG WINDS...SNOW SHOWERS AND SEASONABLY COLD AIR. IT STILL LOOKS LIKE A TREND TO LESS AMPLIFIED FLOW TOWARD THE MIDDLE OF NEXT WEEK. THAT MAY ONLY BE SHORT-LIVED AS MEDIUM RANGE GUIDANCE IS NOW INDICATING A SHARPER PROGRESSIVE TROF MOVING ACROSS THE NRN CONUS MID/LATE WEEK RATHER THAN TROF REMAINING MORE CONFINED TO CANADA THAT HAD BEEN INDICATED IN RECENT DAYS MODEL RUNS. END RESULT IS MODERATING TEMPS AND A DRIER PATTERN HEADING INTO MID WEEK AND THEN A TURN TO COLDER WEATHER LATE WEEK...ACCOMPANIED BY SOME -SHSN AND FOLLOWED BY PROBABLY LIGHT LES OFF LAKE SUPERIOR. BEGINNING SUN...ATTENTION WILL BE ON A STRONG SHORTWAVE SWINGING OUT ACROSS THE CNTRL PLAINS. WAVE WILL GO NEGATIVE TILT AND RAPIDLY DEEPEN AS IT PASSES ACROSS THE GREAT LAKES SUN NIGHT. 12HR 500MB HEIGHT FALLS ARE STILL FCST TO MAX OUT AROUND AN IMPRESSIVE 280M TO THE NE AND E OF GEORGIAN BAY. MAJORITY OF GUIDANCE STILL INDICATES DEEPENING SFC LOW LIFTING NE THRU WI AND SE LAKE SUPERIOR...WHICH WAS THE PREFERRED TRACK 24HRS AGO. THE GFS IS STILL THE OUTLIER WITH A FARTHER E TRACK...PASSING ACROSS THE STRAITS AND DRUMMOND ISLAND. IF ANYTHING...THE GFS HAS BEEN TRENDING VERY SLIGHTLY FARTHER S AND E WITH THE TRACK IN RECENT RUNS. WILL CONTINUE TO USE THE MORE CLIMATOLOGICALLY FAVORED SFC LOW TRACK ACROSS FAR SE LAKE SUPERIOR...REPRESENTED BY THE ECMWF/UKMET/GEM AND 4KM NAM WINDOW. INCREASING HEIGHT FALLS AND STRONG UPPER DIFFLUENCE WITH LEFT EXIT OF 130KT UPPER JET NOSING INTO THE GREAT LAKES WILL SUPPORT AN AREA OF SHRA SPREADING N INTO UPPER MI SUN AFTN...WITH THE HEAVIEST PCPN PROBABLY SLIDING THRU CNTRL/ERN UPPER MI LATE AFTN/EVENING WHERE LOW/MID LEVEL FRONTOGENESIS AND ISENTROPIC ASCENT ARE STRONGEST. WITH SHOWALTER INDEX FALLING TO SLIGHTLY NEGATIVE...WILL CONTINUE A MENTION OF THUNDER OVER ROUGHLY THE E HALF OF THE FCST AREA... GENERALLY ALONG AND E OF EXPECTED SFC LOW TRACK. COLDER AIR WRAPPING IN BEHIND THE SYSTEM WILL CHANGE RAIN TO SNOW RATHER QUICKLY FROM W TO E DURING SUN NIGHT PER CONSENSUS OF MODEL THERMAL FIELDS/SOUNDINGS. POTENTIAL FOR HVY SNOW OR EVEN MDT SNOW IS NOTABLY DIMINISHED FROM WHAT SOME MODEL RUNS SUGGESTED IN RECENT DAYS. BIGGEST PROBLEM IS TIMING OF HOW FAST DEFORMATION PCPN SHIELD DEVELOPS/EXPANDS/ORGANIZES ON NW/W SIDE OF SYSTEM. WITH THE FAST SPEED OF SHORTWAVE THRU THE WRN GREAT LAKES AND WITH SFC/MID LEVEL SYSTEM NOT BECOMING WELL DEVELOPED UNTIL NE OF THE AREA...IT DOESN`T APPEAR THE SYNOPTIC SNOW SHIELD WILL BECOME REALLY ORGANIZED UNTIL IT MOVES INTO NRN ONTARIO TO THE N AND NE OF LAKE SUPERIOR. IT WILL PROBABLY TURN INTO A FAIRLY SUBSTANTIAL SNOW STORM FOR AREAS BTWN LAKE SUPERIOR AND JAMES BAY...ESPECIALLY TOWARD JAMES BAY. AS IT APPEARS NOW...THE STEADIER/HEAVIER PCPN IN THE EVENING OVER THE W WILL PROBABLY FALL MOSTLY AS RAIN. BY THE TIME COLUMN COOLS SUFFICIENTLY FOR A CHANGEOVER TO SNOW...THE SYNOPTIC PCPN WILL BE PULLING OUT. STILL...WITH CYCLONIC FLOW/850MB TEMPS FALLING TO AROUND -9C BY 12Z MON AND DEEPER MOISTURE HANGING AROUND...EXPECT LAKE ENHANCED SNOW TO DEVELOP OFF WRN LAKE SUPERIOR OVERNIGHT. MIGHT SEE A FEW INCHES OF SNOW IN THE HIGHER TERRAIN OF THE W BY SUNRISE MON...BUT WITH DENDRITIC SNOW GROWTH TEMPS ABOVE THE UPWARD MOTION ZONE AND POTENTIALLY EVEN ABOVE THE MOIST LAYER...IT MAY BE TOUGH TO GET A FEW INCHES OF SNOW. STRONG BOUNDARY LAYER WINDS SHOULD TEND TO SPREAD THE LAKE ENHANCED SNOW A BIT FARTHER INLAND THAN IS USUALLY THE CASE. HURON MTNS MAY BE AN AREA TO SEE MOST PERISTENT SNOWFALL. LATE CHANGEOVER TO SNOW OVER THE E WILL FURTHER LIMIT SNOW ACCUMULATIONS IN THAT AREA SUN NIGHT. NO HEADLINES PERTAINING TO SNOW ARE WARRANTED AT THIS TIME. WINDS WILL BE A BIG STORY WITH THE SYSTEM. IN THE WAKE OF THE DEEPENING SFC LOW...MODELS INDICATE NW WINDS OF 45-55KT AT 850MB DURING THE PERIOD OF CAA. 4KM HIGH RES NAM SHOWS WIND GUST POTENTIAL TO A LITTLE OVER 40KT OVER THE KEWEENAW AND TO A LITTLE OVER 50KT ALONG THE LAKESHORE E OF MARQUETTE. ISALLOBARIC WIND COMPONENT WILL ADD SOME ENHANCEMENT AS PRES RISES STRENGTHEN OVER THE AREA IN THE WAKE OF THE DEEPENING LOW. IF ADVY HEADLINES END UP NOT BEING NEEDED FOR SNOWFALL...WIND HEADLINES WILL BE NEEDED. ON LAKE SUPERIOR... HIGH GALES ARE LIKELY ON THE E HALF OF LAKE SUPERIOR WITH DECENT POTENTIAL FOR A PERIOD OF STORM FORCE WINDS LATE OVERNIGHT SUN NIGHT INTO MON MORNING. TRANSITION TO PURE LES WILL OCCUR MON/MON NIGHT UNDER NW FLOW AS 850MB TEMPS FALL TO -10/-11C. LINGERING LIGHT LES WILL WIND DOWN/END OVER WRN UPPER MI MON NIGHT AND OVER NCNTRL UPPER MI TUE MORNING AS AS FLOW BACKS AND WAA GETS UNDERWAY. WITH SFC HIGH PRES RIDGE REACHING WRN UPPER MI LATE MON NIGHT...TEMPS COULD PLUMMET IF CLOUDS CLEAR OUT. NONE OF THE GUIDANCE IS ESPECIALLY COLD. LOWEST GUIDANCE GENERALLY SUGGEST MINS IN THE UPPER TEENS...AND FCST WILL REFLECT THESE COLDER NUMBERS. WAA WED MIGHT YIELD SOME LIGHT PCPN AT THAT TIME. THEN...STRONG SHORTWAVE MOVING ACROSS SRN CANADA WILL SWEEP ASSOCIATED COLD FRONT ACROSS THE AREA WED NIGHT...ACCOMPANIED BY SOME -RA/-SN. LES MAY GET UNDERWAY THU...BUT MODELS HAVE NOT BEEN VERY CONSISTENT ON THE INTENSITY OF THE COLD FOLLOWING THE FRONT. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 644 AM EST SAT NOV 16 2013 SOUTHERLY WINDS WILL INCREASE LOW LEVEL MOISTURE ACROSS UPPER MICHIGAN TODAY AHEAD OF A DISTURBANCE MOVING THROUGH THIS EVENING. THIS INCREASING LOW LEVEL MOISTURE WILL PRODUCE A QUICK TRANSITION FROM VFR CONDITIONS TO IFR CEILINGS THIS AFTERNOON. THEN THE APPROACHING DISTURBANCE WILL BRING A WIDE SWATH OF RAIN THIS EVENING AND LEAD TO LOWER CEILINGS AND VISIBILITIES...ESPECIALLY AT KSAW WHERE THEY WILL BE BORDERLINE AIRFIELD LANDING MINS. MODELS ARE SHOWING DRIER AIR ARRIVING OVER THE WEST AFTER MIDNIGHT AND HAVE TRENDED CEILINGS UP AS THE RAIN ENDS. KSAW WILL HAVE THE LOW CEILINGS REMAINING THROUGH MUCH OF THE NIGHT BUT EXPECT CONDITIONS TO TRY TO IMPROVE BY DAYBREAK. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 521 AM EST SAT NOV 16 2013 SOUTH WINDS WILL INCREASE TO 30KT TODAY AHEAD OF DEEPENING SFC LOW MOVING FROM THE PLAINS TOWARD THE UPPER MISSISSIPPI VALLEY. STRONGEST WINDS TODAY/TONIGHT WILL BE OVER EASTERN PORTIONS OF LAKE SUPERIOR...WHERE THERE MAY BE A FEW GALE GUSTS TO 35KT. STABLE LOW-LEVEL TEMPERATURE PROFILE AND LACK OF PRESSURE FALLS TO NORTH OF LAKE SUPERIOR SHOULD LIMIT FREQUENCY OF GUSTS. WINDS WILL DIMINISH FOR A TIME SUNDAY AS SFC TROF DRIFTS OVERHEAD AND PRES GRADIENT WEAKENS CONSIDERABLY. NEW LOW PRESSURE ORGANIZING OVER THE PLAINS WILL THEN LIFT NE ALONG THE TROF AND RAPIDLY DEEPEN AS IT PASSES ACROSS FAR SE LAKE SUPERIOR INTO NRN ONTARIO. PRES WILL LIKELY FALL BLO 975MB OR 29.0 INCHES AS IT MOVES N OF THE LAKE SUNDAY NIGHT/MON MORNING. IN THE NW FLOW IN THE WAKE OF THE DEEPENING LOW PRES... GALES WILL OCCUR ACROSS ALL BUT FAR WRN LAKE SUPERIOR WITH HIGH END GALES TO STORM FORCE WINDS LIKELY SUN NIGHT/MON MORNING OVER THE E HALF. GIVEN STORM POTENTIAL...A STORM WATCH HAS BEEN ISSUED FOR THE E HALF OF LAKE SUPERIOR. WINDS WILL DIMINISH BELOW 30KT FROM W TO E MON NIGHT...AND A PERIOD OF LIGHT WINDS UNDER 15KT SHOULD OCCUR TUE AS HIGH PRES RIDGE PASSES ACROSS LAKE SUPERIOR. S WINDS WILL THEN RAMP UP TO 20-30KT FOR WED BEHIND THE HIGH AND AHEAD OF THE NEXT APPROACHING LOW PRES TROF. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... STORM WATCH FROM SUNDAY EVENING THROUGH MONDAY AFTERNOON FOR LSZ248>251-265>267. GALE WATCH FROM SUNDAY EVENING THROUGH MONDAY AFTERNOON FOR LSZ241>245-263-264. LAKE MICHIGAN... NONE. && $$ SHORT TERM...SRF LONG TERM...ROLFSON AVIATION...SRF MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
522 AM EST SAT NOV 16 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 521 AM EST SAT NOV 16 2013 SOUTHWESTERLY FLOW IS BEGINNING TO INCREASE OVER THE CWA AS THE UPPER TROUGH AMPLIFIES DUE TO A STRONG SHORTWAVE MOVING SOUTHEAST THROUGH THE PACIFIC NORTHWEST. THIS SHORTWAVE WILL BE THE MAJOR PLAYER TO OUR WEATHER FOR THE SECOND HALF OF THE WEEKEND. FOR THE SHORT TERM...THE SOUTHWESTERLY FLOW ALOFT WILL ALLOW A SHORTWAVE CURRENTLY LOCATED NEAR THE FOUR CORNERS REGION TO MOVE NORTHEAST ACROSS THE UPPER GREAT LAKES LATE THIS AFTERNOON AND EVENING. MOISTURE STREAMING NORTHEAST ON WV IMAGERY IS LEADING TO SOME HIGH CLOUDS OVER MUCH OF UPPER MICHIGAN. IN THE LOWER LEVELS...INITIAL RAP SOUNDINGS SHOWING PLENTY OF DRY AIR BELOW THE HIGH CLOUDS BUT THERE WAS ENOUGH RADIATIONAL COOLING EARLIER THIS EVENING TO PRODUCE SOME PATCHY FOG OVER CENTRAL/EASTERN UPPER MICHIGAN. THE DRIER LOW LEVELS WILL LIKELY BE SHORT LIVED AS 3-5KFT CEILINGS COVER MUCH OF CENTRAL/NORTHERN WISCONSIN AND WILL BE MOVING INTO THE AREA OVER THE NEXT COUPLE OF HOURS. IN ADDITION TO THOSE CLOUDS...MODELS ARE SHOWING THE DEVELOPING 1KFT CEILINGS IN NORTHERN ILLINOIS TO QUICKLY LIFT NORTH AND EXPAND THIS MORNING AND EARLY AFTERNOON...COVERING MUCH OF UPPER MICHIGAN. THE SHORTWAVE WILL BE NEARING THE REGION THIS AFTERNOON AND THERE ARE SEVERAL FEATURES SUPPORTING A BROAD AREA OF RAIN MOVING THROUGH THE AREA LATE THIS AFTERNOON AND EVENING. FIRST...EXPECT THERE TO BE A WEAK COUPLED JET STRUCTURE OVER THE AREA THIS EVENING. BROAD MID LEVEL WARM AIR ADVECTION AND MOISTURE TRANSPORT WILL ACCOMPANY THIS SHORTWAVE...WITH THE EASTERN CWA SEEING THE BEST OF BOTH FEATURES. AT THE SURFACE...THE BROAD LOW DEVELOPING OVER THE CENTRAL/NORTHERN PLAINS WILL SLIDE A TROUGH THROUGH MINNESOTA TODAY AND OVER WESTERN LAKE SUPERIOR TONIGHT. HAVE HIGH CONFIDENCE IN THE FORECAST FOR THIS AFTERNOON/EVENING BASED OFF GREAT MODEL CONSISTENCY. SINCE THE BEST FORCING IS OVER THE SOUTHEAST HALF...WILL HAVE THE HIGHEST POPS/QPF IN THAT AREA BUT THERE WILL BE A PERIOD OF DEFINITE POPS OVER THE ENTIRE AREA. AS FOR QPF...EXPECT VALUES TO RANGE FROM 0.2 OVER THE WEST TO 0.75IN OVER THE EAST...WITH SOME HIGHER AMOUNTS IF THERE ARE SOME EMBEDDED THUNDERSTORMS. AS FOR THUNDER...THERE IS A POCKET OF 50-125J/KG OF MUCAPE AND SHOWALTER VALUES SLIGHTLY BELOW 0 OVER THE EASTERN 2/3RDS OF THE CWA LATE THIS AFTERNOON INTO THE EVENING HOURS. BOTH 00Z NAM AND 21Z SREF PROBABILITIES INDICATE THE POTENTIAL FOR A RUMBLE OF THUNDER OR TWO OVER THE SOUTHEAST PART OF THE CWA...WHICH CORRELATES WELL WITH POCKET OF STEEPER 850-500MB LAPSE RATES MOVING THROUGH AND BEST FORCING. PREVIOUS SHIFT HAD A SLIGHT CHANCE MENTIONED (WHICH SEEMS REASONABLE) AND ONLY MADE MINOR TWEAKS. ALL OF THE FORCING FEATURES WILL SHIFT NORTHEAST AROUND OR SHORTLY AFTER MIDNIGHT (AND MID LEVEL DRYING OCCURS)...SO HAVE A DIMINISHING TREND TO THE POPS FROM SOUTHWEST TO NORTHEAST. WITH THE DEEP MOISTURE DEPARTING...DID TRANSITION THE PRECIP WORDING FROM RAIN TO DRIZZLE OVERNIGHT (MAINLY OVER THE EASTERN AREAS). MODELS MATCH UP WITH THAT IDEA (BLOTCHY LOOK TO QPF IN THE HIGHER RESOLUTION RUNS). DID CONTINUE TO MENTION SOME FOG WITH THE RAIN THIS EVENING...ALTHOUGH THE WIND MIGHT HELP KEEP IT MORE OF A STRATUS WITH ONLY A SLIGHT LOWERING OF VISIBILITIES EXCEPT OVER THE HIGHER TERRAIN. THUS...HAVE KEPT MOST OF THE AREA UNDER PATCHY WORDING...ALTHOUGH DID IT DIMINISH OVER THE WEST OVERNIGHT AS LOWER LEVEL AIR SLIDES IN. FINALLY...WILL SEE INCREASING SOUTHERLY WINDS TODAY WITH A TIGHTENING PRESSURE GRADIENT BETWEEN THE HIGH OFF THE EAST COAST AND TROUGH MOVING EAST THROUGH MINNESOTA. STRONGEST WINDS WILL BE OVER THE EASTERN CWA...WHERE THE LOW LEVEL JET WILL BE LOCATED. WITH THE INCREASING LOW LEVEL MOISTURE AND EXPECTED CLOUD COVER...THINK THAT WILL LIMIT MIXING AND KEEP WINDS IN CHECK (OCCASIONAL GUSTS IN THE 20-30MPH RANGE SEEN ON BUFKIT MOMENTUM TRANSFER). ABOVE NORMAL TEMPERATURES WILL CONTINUE TODAY AND TONIGHT AS WARM AIR SLIDES NORTH OVER THE AREA. THIS WARM AIR WILL REALLY SURGE IN TONIGHT...WHICH COULD CAUSE MOST LOWS TO OCCUR EARLY THIS EVENING AND THEN RISING OVERNIGHT INTO THE UPPER 40S AND AROUND 50. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 521 AM EST SAT NOV 16 2013 LONG TERM WILL START WITH A STRONG STORM SYSTEM LIFTING THRU THE UPPER GREAT LAKES...BRINGING RAIN AND THEN A TRANSITION TO STRONG WINDS...SNOW SHOWERS AND SEASONABLY COLD AIR. IT STILL LOOKS LIKE A TREND TO LESS AMPLIFIED FLOW TOWARD THE MIDDLE OF NEXT WEEK. THAT MAY ONLY BE SHORT-LIVED AS MEDIUM RANGE GUIDANCE IS NOW INDICATING A SHARPER PROGRESSIVE TROF MOVING ACROSS THE NRN CONUS MID/LATE WEEK RATHER THAN TROF REMAINING MORE CONFINED TO CANADA THAT HAD BEEN INDICATED IN RECENT DAYS MODEL RUNS. END RESULT IS MODERATING TEMPS AND A DRIER PATTERN HEADING INTO MID WEEK AND THEN A TURN TO COLDER WEATHER LATE WEEK...ACCOMPANIED BY SOME -SHSN AND FOLLOWED BY PROBABLY LIGHT LES OFF LAKE SUPERIOR. BEGINNING SUN...ATTENTION WILL BE ON A STRONG SHORTWAVE SWINGING OUT ACROSS THE CNTRL PLAINS. WAVE WILL GO NEGATIVE TILT AND RAPIDLY DEEPEN AS IT PASSES ACROSS THE GREAT LAKES SUN NIGHT. 12HR 500MB HEIGHT FALLS ARE STILL FCST TO MAX OUT AROUND AN IMPRESSIVE 280M TO THE NE AND E OF GEORGIAN BAY. MAJORITY OF GUIDANCE STILL INDICATES DEEPENING SFC LOW LIFTING NE THRU WI AND SE LAKE SUPERIOR...WHICH WAS THE PREFERRED TRACK 24HRS AGO. THE GFS IS STILL THE OUTLIER WITH A FARTHER E TRACK...PASSING ACROSS THE STRAITS AND DRUMMOND ISLAND. IF ANYTHING...THE GFS HAS BEEN TRENDING VERY SLIGHTLY FARTHER S AND E WITH THE TRACK IN RECENT RUNS. WILL CONTINUE TO USE THE MORE CLIMATOLOGICALLY FAVORED SFC LOW TRACK ACROSS FAR SE LAKE SUPERIOR...REPRESENTED BY THE ECMWF/UKMET/GEM AND 4KM NAM WINDOW. INCREASING HEIGHT FALLS AND STRONG UPPER DIFFLUENCE WITH LEFT EXIT OF 130KT UPPER JET NOSING INTO THE GREAT LAKES WILL SUPPORT AN AREA OF SHRA SPREADING N INTO UPPER MI SUN AFTN...WITH THE HEAVIEST PCPN PROBABLY SLIDING THRU CNTRL/ERN UPPER MI LATE AFTN/EVENING WHERE LOW/MID LEVEL FRONTOGENESIS AND ISENTROPIC ASCENT ARE STRONGEST. WITH SHOWALTER INDEX FALLING TO SLIGHTLY NEGATIVE...WILL CONTINUE A MENTION OF THUNDER OVER ROUGHLY THE E HALF OF THE FCST AREA... GENERALLY ALONG AND E OF EXPECTED SFC LOW TRACK. COLDER AIR WRAPPING IN BEHIND THE SYSTEM WILL CHANGE RAIN TO SNOW RATHER QUICKLY FROM W TO E DURING SUN NIGHT PER CONSENSUS OF MODEL THERMAL FIELDS/SOUNDINGS. POTENTIAL FOR HVY SNOW OR EVEN MDT SNOW IS NOTABLY DIMINISHED FROM WHAT SOME MODEL RUNS SUGGESTED IN RECENT DAYS. BIGGEST PROBLEM IS TIMING OF HOW FAST DEFORMATION PCPN SHIELD DEVELOPS/EXPANDS/ORGANIZES ON NW/W SIDE OF SYSTEM. WITH THE FAST SPEED OF SHORTWAVE THRU THE WRN GREAT LAKES AND WITH SFC/MID LEVEL SYSTEM NOT BECOMING WELL DEVELOPED UNTIL NE OF THE AREA...IT DOESN`T APPEAR THE SYNOPTIC SNOW SHIELD WILL BECOME REALLY ORGANIZED UNTIL IT MOVES INTO NRN ONTARIO TO THE N AND NE OF LAKE SUPERIOR. IT WILL PROBABLY TURN INTO A FAIRLY SUBSTANTIAL SNOW STORM FOR AREAS BTWN LAKE SUPERIOR AND JAMES BAY...ESPECIALLY TOWARD JAMES BAY. AS IT APPEARS NOW...THE STEADIER/HEAVIER PCPN IN THE EVENING OVER THE W WILL PROBABLY FALL MOSTLY AS RAIN. BY THE TIME COLUMN COOLS SUFFICIENTLY FOR A CHANGEOVER TO SNOW...THE SYNOPTIC PCPN WILL BE PULLING OUT. STILL...WITH CYCLONIC FLOW/850MB TEMPS FALLING TO AROUND -9C BY 12Z MON AND DEEPER MOISTURE HANGING AROUND...EXPECT LAKE ENHANCED SNOW TO DEVELOP OFF WRN LAKE SUPERIOR OVERNIGHT. MIGHT SEE A FEW INCHES OF SNOW IN THE HIGHER TERRAIN OF THE W BY SUNRISE MON...BUT WITH DENDRITIC SNOW GROWTH TEMPS ABOVE THE UPWARD MOTION ZONE AND POTENTIALLY EVEN ABOVE THE MOIST LAYER...IT MAY BE TOUGH TO GET A FEW INCHES OF SNOW. STRONG BOUNDARY LAYER WINDS SHOULD TEND TO SPREAD THE LAKE ENHANCED SNOW A BIT FARTHER INLAND THAN IS USUALLY THE CASE. HURON MTNS MAY BE AN AREA TO SEE MOST PERISTENT SNOWFALL. LATE CHANGEOVER TO SNOW OVER THE E WILL FURTHER LIMIT SNOW ACCUMULATIONS IN THAT AREA SUN NIGHT. NO HEADLINES PERTAINING TO SNOW ARE WARRANTED AT THIS TIME. WINDS WILL BE A BIG STORY WITH THE SYSTEM. IN THE WAKE OF THE DEEPENING SFC LOW...MODELS INDICATE NW WINDS OF 45-55KT AT 850MB DURING THE PERIOD OF CAA. 4KM HIGH RES NAM SHOWS WIND GUST POTENTIAL TO A LITTLE OVER 40KT OVER THE KEWEENAW AND TO A LITTLE OVER 50KT ALONG THE LAKESHORE E OF MARQUETTE. ISALLOBARIC WIND COMPONENT WILL ADD SOME ENHANCEMENT AS PRES RISES STRENGTHEN OVER THE AREA IN THE WAKE OF THE DEEPENING LOW. IF ADVY HEADLINES END UP NOT BEING NEEDED FOR SNOWFALL...WIND HEADLINES WILL BE NEEDED. ON LAKE SUPERIOR... HIGH GALES ARE LIKELY ON THE E HALF OF LAKE SUPERIOR WITH DECENT POTENTIAL FOR A PERIOD OF STORM FORCE WINDS LATE OVERNIGHT SUN NIGHT INTO MON MORNING. TRANSITION TO PURE LES WILL OCCUR MON/MON NIGHT UNDER NW FLOW AS 850MB TEMPS FALL TO -10/-11C. LINGERING LIGHT LES WILL WIND DOWN/END OVER WRN UPPER MI MON NIGHT AND OVER NCNTRL UPPER MI TUE MORNING AS AS FLOW BACKS AND WAA GETS UNDERWAY. WITH SFC HIGH PRES RIDGE REACHING WRN UPPER MI LATE MON NIGHT...TEMPS COULD PLUMMET IF CLOUDS CLEAR OUT. NONE OF THE GUIDANCE IS ESPECIALLY COLD. LOWEST GUIDANCE GENERALLY SUGGEST MINS IN THE UPPER TEENS...AND FCST WILL REFLECT THESE COLDER NUMBERS. WAA WED MIGHT YIELD SOME LIGHT PCPN AT THAT TIME. THEN...STRONG SHORTWAVE MOVING ACROSS SRN CANADA WILL SWEEP ASSOCIATED COLD FRONT ACROSS THE AREA WED NIGHT...ACCOMPANIED BY SOME -RA/-SN. LES MAY GET UNDERWAY THU...BUT MODELS HAVE NOT BEEN VERY CONSISTENT ON THE INTENSITY OF THE COLD FOLLOWING THE FRONT. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 1223 AM EST SAT NOV 16 2013 EXPECT VFR CONDITIONS OVERNIGHT BEFORE THE ARRIVAL OF GREATER LOW LEVEL MOISTURE WITH INCREASING SRLY FLOW BRINGS MVFR CIGS INTO THE AREA SATURDAY MORNING. LLWS WAS MENTIONED AT ALL TAF SITES WITH 40 KNOT WINDS EXPECTED ABOVE A STRENGTHENING INVERSION. THE ONSET OF IFR CIGS IS EXPETED EARLIEST AT SAW WITH UPSLOPE SRLY FLOW. BY LATE AFTERNOON AS RAIN ARRIVES INTO THE AREA...CONDITIONS SHOULD ALSO DROP TO IFR AT CMX/IWD. ALTHOUGH FOG WILL ALSO DEVELOP...RAIN SHOULD HELP KEEP THE VSBY FROM FALLING BLO 1-2SM SATURDAY EVENING. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 521 AM EST SAT NOV 16 2013 SOUTH WINDS WILL INCREASE TO 30KT TODAY AHEAD OF DEEPENING SFC LOW MOVING FROM THE PLAINS TOWARD THE UPPER MISSISSIPPI VALLEY. STRONGEST WINDS TODAY/TONIGHT WILL BE OVER EASTERN PORTIONS OF LAKE SUPERIOR...WHERE THERE MAY BE A FEW GALE GUSTS TO 35KT. STABLE LOW-LEVEL TEMPERATURE PROFILE AND LACK OF PRESSURE FALLS TO NORTH OF LAKE SUPERIOR SHOULD LIMIT FREQUENCY OF GUSTS. WINDS WILL DIMINISH FOR A TIME SUNDAY AS SFC TROF DRIFTS OVERHEAD AND PRES GRADIENT WEAKENS CONSIDERABLY. NEW LOW PRESSURE ORGANIZING OVER THE PLAINS WILL THEN LIFT NE ALONG THE TROF AND RAPIDLY DEEPEN AS IT PASSES ACROSS FAR SE LAKE SUPERIOR INTO NRN ONTARIO. PRES WILL LIKELY FALL BLO 975MB OR 29.0 INCHES AS IT MOVES N OF THE LAKE SUNDAY NIGHT/MON MORNING. IN THE NW FLOW IN THE WAKE OF THE DEEPENING LOW PRES... GALES WILL OCCUR ACROSS ALL BUT FAR WRN LAKE SUPERIOR WITH HIGH END GALES TO STORM FORCE WINDS LIKELY SUN NIGHT/MON MORNING OVER THE E HALF. GIVEN STORM POTENTIAL...A STORM WATCH HAS BEEN ISSUED FOR THE E HALF OF LAKE SUPERIOR. WINDS WILL DIMINISH BELOW 30KT FROM W TO E MON NIGHT...AND A PERIOD OF LIGHT WINDS UNDER 15KT SHOULD OCCUR TUE AS HIGH PRES RIDGE PASSES ACROSS LAKE SUPERIOR. S WINDS WILL THEN RAMP UP TO 20-30KT FOR WED BEHIND THE HIGH AND AHEAD OF THE NEXT APPROACHING LOW PRES TROF. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... STORM WATCH FROM SUNDAY EVENING THROUGH MONDAY AFTERNOON FOR LSZ248>251-265>267. GALE WATCH FROM SUNDAY EVENING THROUGH MONDAY AFTERNOON FOR LSZ241>245-263-264. LAKE MICHIGAN... NONE. && $$ SHORT TERM...SRF LONG TERM...ROLFSON AVIATION...JLB MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS RALEIGH NC
940 AM EST SAT NOV 16 2013 .SYNOPSIS... WEAK HIGH PRESSURE WILL EXTEND ACROSS CENTRAL NC TODAY THEN DRIFT EAST TONIGHT AND SUNDAY. A STRONG COLD FRONT WILL APPROACH FROM THE WEST SUNDAY AND CROSS OUR AREA SUNDAY NIGHT THROUGH EARLY MONDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 940 AM SATURDAY... REST OF TODAY: AS THE PREVIOUS SHIFT NOTED... THE BIGGEST CHALLENGE TODAY IS THE EXTENT OF CLOUD COVER AND ITS EFFECTS ON TEMPS. THE 12Z GSO SOUNDING SHOWED DEEP NEAR-SATURATION EXTENDING UP TO 650 MB... AND AREA PILOT REPORTS THIS MORNING INDICATE CLOUD DEPTHS UP TO 3K FT. TRIAD FORECAST SOUNDINGS FROM RECENT RAP MODEL RUNS DID NOT DEPICT THE CLOUD DEPTH WELL (LITTLE TOO DRY ABOVE 850 MB)... ALTHOUGH THE UPSTREAM 12Z FFC SOUNDING DOES SUGGEST WE`LL SEE SOME DRYING ALOFT (ABOVE 900 MB) THROUGH THE DAY. THE VERY LIGHT NEAR-SURFACE WINDS ALONG WITH THE STABILITY OF THE LOWEST 50-100 MB WILL LIMIT VERTICAL AND HORIZONTAL MIXING HOWEVER WITH THIS AIR MASS BANKED UP AGAINST THE HIGHER TERRAIN... AND EXPECT THAT THESE CLOUDS WILL HOLD FIRM FOR MUCH OF THE DAY ACROSS OUR WRN CWA. THE LIGHTER WINDS IN THE ERN CWA WILL DISCOURAGE MIXING EVEN MORE... AND A RECENT AMDAR AIRCRAFT SOUNDING FROM RDU SHOWS THE MOIST LAYER STRETCHING UP TO 750 MB... SO THE FEW BREAKS AND THIN SPOTS CURRENTLY OVER THE CENTRAL/ERN PIEDMONT MAY BE THE PEAK OF SUNSHINE UNTIL LATER THIS AFTERNOON (AFTER 3 PM). ALL OF THIS SHOULD PUT A DAMPER ON TEMPS... AND BASED ON THE LATEST READINGS... WE MAY ONLY SEE READINGS CLIMB ANOTHER 10 OR SO DEGREES THROUGH THE DAY. WILL NUDGE HIGHS SLIGHT DOWNWARD IN THE WEST AND UPWARD IN THE EAST AND SOUTH (WHICH IS SEEING THE MOST SUNSHINE THIS MORNING). HIGHS 62 NW TO 72 EAST. -GIH TONIGHT...LIGHT/NEAR CALM WIND REGIME AND PLENTY OF MOISTURE IN THE LOWEST 5K-8K FT SUGGEST A RETURN OF LOW OVERCAST WITH THE POTENTIAL FOR AREAS OF FOG. COULD SEE SOME DRIZZLE THEN ISENTROPIC LIFT MARGINAL AT BEST. THE MODIFYING AIR MASS AND EXTENSIVE CLOUD COVER WILL MAINTAIN RELATIVELY MILD OVERNIGHT TEMPS FOR THIS TIME OF YEAR. MIN TEMPS GENERALLY IN THE LOWER 50S. -WSS && .SHORT TERM /SUNDAY AND SUNDAY NIGHT/... AS OF 315 AM SATURDAY... SUNDAY...S/W RIDGE EXITS OUR REGION EARLY SUNDAY. THIS WILL ALLOW A S/W IN THE NORTHERN STREAM TO PROGRESS E-NE FROM THE CENTRAL-NORTHERN PLAINS INTO THE WESTERN LAKES BY EARLY SUNDAY EVENING. THE SFC COLD FRONT ATTENDANT WITH THE S/W SHOULD STRETCH FROM LAKE MICHIGAN SSW TO NEAR MEMPHIS. THE APPROACH OF THIS FRONTAL SYSTEM WILL INDUCE AND STRENGTHEN A SLY FLOW ACROSS CENTRAL NC BY SUNDAY AFTERNOON. WHILE CLOUDINESS WILL BE QUITE EXTENSIVE...THE WARM SLY FLOW SHOULD BOOST TEMPS INTO THE 70-75 DEGREE RANGE. IF A FEW RENEGADE SHOWERS WERE TO OCCUR SUNDAY AFTERNOON ACROSS THE WEST...THESE SHOWERS MAY KNOCK TEMPS DOWN A FEW DEGREES. OTHERWISE RAIN CHANCES THROUGH SUNSET APPEAR MINIMAL. SUNDAY NIGHT...ATMOSPHERE WILL BE CHARACTERIZED AS A HIGH SHEAR/LOW CAPE ENVIRONMENT AS A STRENGTHENING LOW LEVEL JET WILL CROSS OUR REGION OVERNIGHT. THIS WILL RESULT IN BULK SHEAR VALUES INT HE 35-50KT RANGE...SUPPORTIVE OF ORGANIZED CONVECTION. CURRENTLY MODEL INSTABILITY LACKING WITH MUCAPE VALUES NO WORSE THAN 250-300 J/KG EXPECTED. REVIEW OF GFS BUFKIT SOUNDING DEPICT A RATHER EXTENSIVE WARM LAYER IN THE 850-700MB LAYER. MID LEVEL LAPSE RATES APPEAR TO BE NO WORSE THAN 5.5 DEG C/KM. DO WONDER IF MODEL INSTABILITY MAY BE UNDERDONE AS SFC DEWPOINTS HAVE THE POTENTIAL TO RECOVER INTO THE LOW-MID 60S OVER MOST OF CENTRAL NC. THUS CANNOT TOTALLY RULE OUT THE POSSIBILITY OF A STRONG OR SEVERE STORMS OVERNIGHT SUNDAY NIGHT. HOWEVER...SUCH OCCURRENCE APPEARS TO BE VERY LIMITED AT THIS TIME SO REFRAIN FROM MENTIONING THUNDER AT THIS TIME AND AWAIT LATER MODEL GUIDANCE/UPDATES. APPEARS TO BE FAIRLY DEEP LIFT WITH THE FRONT AND MOISTURE PLENTIFUL. HAVE INCREASES POPS TO LIKELY OR LOW END CATEGORICAL ACROSS THE REGION SUNDAY AS TH SFC FRONT SHOULD BE ON OUR WESTERN PERIPHERY PRIOR TO DAYBREAK MONDAY. VERY MILD SUNDAY NIGHT WITH MIN TEMPS NEAR 60 NW TO LOW-MID 60S ELSEWHERE. && .LONG TERM /MONDAY THROUGH FRIDAY/... AS OF 315 AM SATURDAY... MONDAY AND MONDAY NIGHT: THE SURFACE COLD FRONT MENTIONED IN THE SHORT TERM IS EXPECTED TO CROSS CENTRAL NC MONDAY MORNING INTO THE EARLY AFTERNOON... WITH THE BEST CHANCE FOR SHOWERS... AND PERHAPS EVEN A FEW STORMS... IN ADVANCE OF THE FRONT. FOR NOW... WILL SHOW THE HIGHEST POPS ACROSS EASTERN AND SOUTHEASTERN PORTIONS OF THE AREA FOR THE MORNING (SLIGHT CHANCE NW TO LIKELY E/SE)... WITH ONLY A LINGERING CHANCE IN OUR FAR EAST/SOUTHEAST BY AFTERNOON. THE MAIN DYNAMICS ARE EXPECTED TO PASS WELL TO THE NORTH OF THE AREA. GIVEN THIS AND THE TIME OF DAY (MORNING) ALONG WITH THE GOOD LOW LEVEL JET PROGGED TO BE TO THE EAST OF CENTRAL NC BY 12Z MONDAY... WE DO NOT ANTICIPATE ANY SEVERE WEATHER. THE GOOD PUSH OF COLD AIR IS EXPECTED TO LAG THE FRONT THOUGH... WITH DOWNSLOPE FLOW ON MONDAY. GIVEN THE DOWNSLOPE FLOW AND QUICKLY CLEARING SKIES BEHIND THE FRONT... ALONG WITH TEMPS STARTING OUT GENERALLY IN THE 60S ACROSS THE AREA... EXPECT HIGH TEMPS WILL BE AROUND 70 NORTHWEST TO THE MID 70S... MAYBE EVEN UPPER 70S... SOUTHEAST. HIGH PRESSURE WILL BUILD INTO THE AREA ON MONDAY NIGHT WITH LOW TEMPS DRIVEN BY CAA. LOWS ON TUESDAY MORNING ARE EXPECTED TO RANGE FROM THE UPPER 30S NORTH TO LOWER 40S SOUTH... WITH A NORTHWESTERLY TO NORTHERLY WIND. TUESDAY THROUGH FRIDAY: SURFACE HIGH PRESSURE CENTERED ACROSS THE OHIO VALLEY/GREAT LAKES REGION START THE PERIOD IS EXPECTED TO MOVE EASTWARD AND OFF THE NORTHEAST/NEW ENGLAND COAST BY THURSDAY... WHILE EXTENDING SOUTHWARD INTO CENTRAL NC. A LOW AMPLITUDE FLOW ALOFT WILL PERSIST ACROSS THE REGION GENERALLY THROUGH THE REMAINDER OF THE FORECAST PERIOD... ALTHOUGH HEIGHTS ALOFT WILL SLOWLY RISE THROUGH THIS TIMEFRAME. MEDIUM RANGE MODELS ARE STRUGGLING HOW TO HANDEL THE EVOLUTION OF THE LARGE SCALE FLOW PATTERN THOUGH... AT THE END OF THE FORECAST PERIOD. NEAR THE END OF THE PERIOD MEDIUM RANGE MODELS BEGIN TO TREND TO AN ERN PAC/WEST COAST RIDGE AND DOWNSTREAM TROUGHING PATTERN. FOR NOW IT APPEARS THAT ANY SYSTEM ASSOCIATED WITH THIS NEXT APPROACHING TROUGH WILL HOLD OFF UNTIL BEYOND THE MEDIUM RANGE. THUS... FOR US WE SHOULD SEE DRY CONDITIONS FOR THE REMAINDER OF THE WEEK WITH SLOWLY MODERATING TEMPS. HOWEVER... SKIES WILL BE SUNNY TO START THE PERIOD... THEN TRANSITION TO PARTLY TO MOSTLY CLOUDY WITH BOTH INCREASING HIGH LEVEL MOISTURE LATE WEEK FROM THE WEST ALONG WITH EASTERLY FLOW ADVECTING IN MOISTURE OFF THE ATLANTIC ON THURSDAY INTO FRIDAY AS THE SURFACE HIGH SHIFTS OFFSHORE. HIGH TEMPS GENERALLY BE IN THE 50S... WITH LOWS RANGING FROM GENERALLY 30 TO 40 DEGREES... COLDEST ON WEDNESDAY MORNING (WHERE A FEW UPPER 20S CANT BE RULED OUT). && .AVIATION /12Z SATURDAY THROUGH WEDNESDAY/... AS OF 645 AM SATURDAY... WIDESPREAD LOW END MVFR/IFR CEILINGS ACROSS CENTRAL NC WITH POCKETS OF MVFR VISIBILITY DUE TO FOG WILL PERSIST ACROSS CENTRAL NC UNTIL 14Z. AFTER WHICH...VISIBILITIES WILL IMPROVE TO GREATER THAN 6 MILES AND CEILINGS WILL GRADUALLY LIFT THOUGH REMAIN IN THE MVFR RANGE UNTIL 18Z-20Z. BY MID AFTERNOON...EXPECT CEILINGS TO CONTINUE TO LIFT AND EVENTUALLY SCATTER AT MOST SPOTS WITH CLOUD BASES 3000-4000FT. THE LOWER LAYERS OF THE ATMOSPHERE WILL REMAIN MOIST LATE TODAY THROUGH TONIGHT. WITH LITTLE MIXING ANTICIPATED...EXPECT CEILINGS TO LOWER SHORTLY AFTER SUNSET WITH WIDESPREAD LOW END MVFR/IFR CEILINGS ANTICIPATED THIS EVENING AND PERSISTING INTO SUNDAY MORNING. AGAIN...EXPECT A GRADUAL IMPROVEMENT IN CEILINGS LATE SUNDAY MORNING INTO SUNDAY AFTERNOON. AN APPROACHING COLD FRONT WILL INCREASE THE THREAT FOR SHOWERS AND ASSOCIATED MVFR VISIBILITIES...ESPECIALLY SUNDAY NIGHT THROUGH EARLY MONDAY. SOUTHERLY SFC WINDS WILL BECOME BREEZY AHEAD OF THE FRONT LATE SUNDAY INTO SUNDAY NIGHT WITH SUSTAINED WINDS 10-15KTS AND GUST 20-25KTS PROBABLE SUNDAY NIGHT. THE COLD FRONT WILL SWEEP THROUGH CENTRAL NC MONDAY MORNING. BEHIND THE FRONT...MUCH DRIER AIR WILL QUICKLY DIMINISH THE SHOWERS AND DISSIPATE THE CLOUD COVERAGE. VFR CONDITIONS SHOULD COVER CENTRAL NC MONDAY AFTERNOON AND PERSIST THROUGH WEDNESDAY. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...WSS NEAR TERM...HARTFIELD/WSS SHORT TERM...WSS LONG TERM...BSD AVIATION...WSS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
947 AM CST SAT NOV 16 2013 .UPDATE... ISSUED AT 947 AM CST SAT NOV 16 2013 RADAR RETURNS CONTINUE OVER WESTERN AND NORTH CENTRAL NORTH DAKOTA AND HAVE EXPANDED AREAL COVERAGE OF SLIGHT CHANCE POPS. ALSO ADDED A SLIGHT CHANCE OF PRECIPITATION OVER THE FAR SOUTHEAST COUNTIES AS RETURNS HAVE INCREASED HERE AS WELL OVER THE PAST FEW HOURS. PRECIPITATION WILL BE RAIN IN THE SOUTHEAST WITH A RAIN SNOW MIX NORTH AND WEST FOR ANOTHER HOUR OR TWO...BEFORE RAIN THIS AFTERNOON. PRECIPITATION AMOUNTS TODAY WILL BE LIGHT. A FEW AREAS OF SUN OVER THE FAR SOUTH CENTRAL YET THIS MORNING...BUT CLOUDS WILL CONTINUE TO INCREASE DURING THE DAY. WILL TAKE A CLOSER LOOK AT TEMPERATURES LATE MORNING/EARLY THIS AFTERNOON. UPDATE ISSUED AT 629 AM CST SAT NOV 16 2013 EARLY MORNING RADAR MOSAIC SHOWS A FEW RETURNS ACROSS THE NORTHWEST AND SOUTHEAST PARTS OF THE STATE. THE 12Z KBIS SOUNDING SHOWS THERE IS QUITE A BIT OF DRY LOW LEVEL AIR TO OVERCOME...SO MAINLY VIRGA IS EXPECTED OVER THE NEXT FEW HOURS. THE EXCEPTION WOULD BE IN THE NORTHWEST WHERE THE LATEST RAP SUGGESTS THERE COULD BE LIGHT PRECIPITATION THIS MORNING. ESTEVAN HAS REPORTED A FEW FLURRIES IN THE PAST HOUR...SO WILL INCREASE THE COVERAGE OF THE SLIGHT CHANCES POPS THIS MORNING TO FALL IN LINE CLOSER TO THE COVERAGE SHOWN BY THE RAP. DO NOT EXPECT MUCH ACCUMULATION...THUS KEPT POPS LOW. UPDATED TEMPERATURES TO BETTER REFLECT CURRENT CONDITIONS...OTHERWISE THE FORECAST LOOKS TO BE IN GOOD SHAPE. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 310 AM CST SAT NOV 16 2013 A WINTER WEATHER ADVISORY WILL NOT BE ISSUED FOR THIS EVENT...AT LEAST NOT WITH THIS FORECAST CYCLE...BASED ON CURRENT EXPECTATIONS OF JUST AN INCH OR TWO TOTAL SNOWFALL SATURDAY NIGHT THROUGH SUNDAY. WE ARE DEEP ENOUGH NOW INTO THE SNOW SEASON WHERE AN ADVISORY IS NOT JUSTIFIED. WE MAY OPT TO HIGHLIGHT THE EVENT THROUGH A SPECIAL WEATHER STATEMENT AS SUNDAY WILL BE WINDY AND MUCH COLDER. TWO POINTS OF INTEREST FOR THE SHORT TERM. THE FIRST IS THE ABOVE NORMAL TEMPERATURES FOR TODAY...SATURDAY. ENJOY IT IF YOU CAN AS HIGH TEMPERATURES WILL BE 5 TO 10 DEGREES ABOVE MID NOVEMBER NORMALS. COOLER THAN FRIDAY...BUT STILL ABOVE NORMAL. THE SECOND POINT IS THE COLDER WEATHER MOVING IN FOR TONIGHT WITH RAIN CHANGING TO SNOW. FOR TODAY...SURFACE HIGH PRESSURE AND MID LEVEL RIDGING WILL SLIDE / SHIFT OFF TO THE EAST AS AN OPEN MID LEVEL WAVE APPROACHES FROM THE NORTHWEST. AHEAD OF THE SURFACE LOW...CLOUDS WERE ALREADY ADVANCING INTO THE WESTERN PART OF THE FORECAST AREA...AND WILL MAKE FOR A MOSTLY CLOUDY AFTERNOON ACROSS ALL OF THE FORECAST AREA. A WEAK WARM FRONT SLIDING THROUGH LATER TODAY WILL PUSH TEMPERATURES INTO THE 40S FOR HIGHS...AND BRING THE CHANCE FOR AN ISOLATED RAIN SHOWER TO THE WEST. FOR TONIGHT...LARGE SCALE LIFTING INCREASES AS THE MID LEVEL AND SURFACE WAVE APPROACH. COOLING WILL BE DELAYED...AS WE WILL BE ON THE SO CALLED WARM SIDE OF STORM...UNTIL AFTER 9 PM OR SO. PRECIPITATION STARTS AS RAIN AND THEN TRANSITIONS TO SNOW AS THE ATMOSPHERE COOLS. THE CHANGE TO SNOW OCCURS ALONG HIGHWAY 2 AROUND 9 PM CST...AND ALONG I-94 AROUND 11 PM OR MIDNIGHT CST. THE SNOW THROUGH DAYBREAK SUNDAY WILL BE LIGHT IN INTENSITY. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 310 AM CST SAT NOV 16 2013 SUNDAY WILL BEGIN WITH A LARGE TROUGH ACROSS THE CENTRAL UNITED STATES WHICH HELPS PUSH ANOTHER COLD FRONT THROUGH THE NORTHERN PLAINS. SHORT TERM MODELS HAVE COME INTO BETTER AGREEMENT REGARDING PRECIPITATION CHANCES...AND SUGGEST HIGHER CHANCES FOR SUNDAY MORNING. HAVE INCREASED POPS ACCORDINGLY AND NOW HAVE POPS APPROACHING CATEGORICAL IN THE NORTHWEST. IT APPEARS THE MAJORITY OF THE PRECIPITATION WILL FALL AS SNOW AS COLDER AIR WORKS IT WAY INTO THE REGION. SNOW AMOUNTS SUNDAY SHOULD GENERALLY STAY LESS THAN 1.5 INCHES. HIGH TEMPERATURES IN THE MID 20S TO MID 30S ON SUNDAY WILL BE MUCH COOLER THAN THOSE EXPECTED FOR TODAY (SATURDAY). THE COLDER TEMPERATURES COMBINED WITH A GUSTY NORTHWESTERLY WIND WILL MAKE FOR A RATHER BLUSTERY DAY. SURFACE HIGH PRESSURE BUILDS IN SUNDAY NIGHT...AND WILL GO DRY ACROSS THE FORECAST AREA. THAT BEING SAID...SOME MODEL SOLUTIONS DO SUGGEST THE POSSIBILITY OF LINGERING LIGHT SNOW IN THE FAR EAST EARLY SUNDAY EVENING...BUT DID NOT FEEL CONFIDENT ENOUGH TO ADD A POP AT THE MOMENT. H5 HEIGHTS RISE MONDAY WITH WARMER AIR RETURNING TO THE NORTHERN PLAINS FOR EARLY NEXT WEEK. THE WARMER AIR DOES NOT STAY IN PLACE FOR VERY LONG WITH ANOTHER COLD FRONT DROPPING ACROSS DAKOTAS WEDNESDAY INTO WEDNESDAY NIGHT. THE FRONT WILL ALSO BRING ANOTHER CHANCE OF PRECIPITATION...AGAIN MAINLY IN THE FORM OF SNOW. AT THE MOMENT...IT DOES NOT APPEAR TO BE A SIGNIFICANT PRECIPITATION MAKER. DRIER WEATHER TAKES HOLD AGAIN FOR THURSDAY AND FRIDAY. WARMER AIR RETURNS AGAIN FRIDAY INTO NEXT WEEKEND. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 947 AM CST SAT NOV 16 2013 VFR WEATHER WILL PREVAIL THROUGH THE DAYLIGHT HOURS OF SATURDAY. HIGH AND MID LEVEL CLOUDS WILL INCREASE FROM THE NORTHWEST THROUGH THE DAY...AND LOWER AS MOISTURE INCREASES AFTER 16/18Z. A FEW SNOW FLURRIES ARE POSSIBLE FOR THE AREA AROUND KISN THIS MORNING...THEN ISOLATED RAIN SHOWERS SPREADING THROUGH KISN-KMOT-KDIK AFTER 16/22Z. SURFACE WINDS SATURDAY WILL BE 10 KNOTS OR LESS. THE RAIN SHOWERS WILL CHANGE TO SNOW AS LOW PRESSURE APPROACHES AFTER 17/03Z...WITH MVFR CIGS ALSO POSSIBLE. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...TWH SHORT TERM...JPM LONG TERM...CK AVIATION...TWH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
643 AM CST SAT NOV 16 2013 .UPDATE... ISSUED AT 629 AM CST SAT NOV 16 2013 EARLY MORNING RADAR MOSAIC SHOWS A FEW RETURNS ACROSS THE NORTHWEST AND SOUTHEAST PARTS OF THE STATE. THE 12Z KBIS SOUNDING SHOWS THERE IS QUITE A BIT OF DRY LOW LEVEL AIR TO OVERCOME...SO MAINLY VIRGA IS EXPECTED OVER THE NEXT FEW HOURS. THE EXCEPTION WOULD BE IN THE NORTHWEST WHERE THE LATEST RAP SUGGESTS THERE COULD BE LIGHT PRECIPITATION THIS MORNING. ESTEVAN HAS REPORTED A FEW FLURRIES IN THE PAST HOUR...SO WILL INCREASE THE COVERAGE OF THE SLIGHT CHANCES POPS THIS MORNING TO FALL IN LINE CLOSER TO THE COVERAGE SHOWN BY THE RAP. DO NOT EXPECT MUCH ACCUMULATION...THUS KEPT POPS LOW. UPDATED TEMPERATURES TO BETTER REFLECT CURRENT CONDITIONS...OTHERWISE THE FORECAST LOOKS TO BE IN GOOD SHAPE. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 310 AM CST SAT NOV 16 2013 A WINTER WEATHER ADVISORY WILL NOT BE ISSUED FOR THIS EVENT...AT LEAST NOT WITH THIS FORECAST CYCLE...BASED ON CURRENT EXPECTATIONS OF JUST AN INCH OR TWO TOTAL SNOWFALL SATURDAY NIGHT THROUGH SUNDAY. WE ARE DEEP ENOUGH NOW INTO THE SNOW SEASON WHERE AN ADVISORY IS NOT JUSTIFIED. WE MAY OPT TO HIGHLIGHT THE EVENT THROUGH A SPECIAL WEATHER STATEMENT AS SUNDAY WILL BE WINDY AND MUCH COLDER. TWO POINTS OF INTEREST FOR THE SHORT TERM. THE FIRST IS THE ABOVE NORMAL TEMPERATURES FOR TODAY...SATURDAY. ENJOY IT IF YOU CAN AS HIGH TEMPERATURES WILL BE 5 TO 10 DEGREES ABOVE MID NOVEMBER NORMALS. COOLER THAN FRIDAY...BUT STILL ABOVE NORMAL. THE SECOND POINT IS THE COLDER WEATHER MOVING IN FOR TONIGHT WITH RAIN CHANGING TO SNOW. FOR TODAY...SURFACE HIGH PRESSURE AND MID LEVEL RIDGING WILL SLIDE / SHIFT OFF TO THE EAST AS AN OPEN MID LEVEL WAVE APPROACHES FROM THE NORTHWEST. AHEAD OF THE SURFACE LOW...CLOUDS WERE ALREADY ADVANCING INTO THE WESTERN PART OF THE FORECAST AREA...AND WILL MAKE FOR A MOSTLY CLOUDY AFTERNOON ACROSS ALL OF THE FORECAST AREA. A WEAK WARM FRONT SLIDING THROUGH LATER TODAY WILL PUSH TEMPERATURES INTO THE 40S FOR HIGHS...AND BRING THE CHANCE FOR AN ISOLATED RAIN SHOWER TO THE WEST. FOR TONIGHT...LARGE SCALE LIFTING INCREASES AS THE MID LEVEL AND SURFACE WAVE APPROACH. COOLING WILL BE DELAYED...AS WE WILL BE ON THE SO CALLED WARM SIDE OF STORM...UNTIL AFTER 9 PM OR SO. PRECIPITATION STARTS AS RAIN AND THEN TRANSITIONS TO SNOW AS THE ATMOSPHERE COOLS. THE CHANGE TO SNOW OCCURS ALONG HIGHWAY 2 AROUND 9 PM CST...AND ALONG I-94 AROUND 11 PM OR MIDNIGHT CST. THE SNOW THROUGH DAYBREAK SUNDAY WILL BE LIGHT IN INTENSITY. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 310 AM CST SAT NOV 16 2013 SUNDAY WILL BEGIN WITH A LARGE TROUGH ACROSS THE CENTRAL UNITED STATES WHICH HELPS PUSH ANOTHER COLD FRONT THROUGH THE NORTHERN PLAINS. SHORT TERM MODELS HAVE COME INTO BETTER AGREEMENT REGARDING PRECIPITATION CHANCES...AND SUGGEST HIGHER CHANCES FOR SUNDAY MORNING. HAVE INCREASED POPS ACCORDINGLY AND NOW HAVE POPS APPROACHING CATEGORICAL IN THE NORTHWEST. IT APPEARS THE MAJORITY OF THE PRECIPITATION WILL FALL AS SNOW AS COLDER AIR WORKS IT WAY INTO THE REGION. SNOW AMOUNTS SUNDAY SHOULD GENERALLY STAY LESS THAN 1.5 INCHES. HIGH TEMPERATURES IN THE MID 20S TO MID 30S ON SUNDAY WILL BE MUCH COOLER THAN THOSE EXPECTED FOR TODAY (SATURDAY). THE COLDER TEMPERATURES COMBINED WITH A GUSTY NORTHWESTERLY WIND WILL MAKE FOR A RATHER BLUSTERY DAY. SURFACE HIGH PRESSURE BUILDS IN SUNDAY NIGHT...AND WILL GO DRY ACROSS THE FORECAST AREA. THAT BEING SAID...SOME MODEL SOLUTIONS DO SUGGEST THE POSSIBILITY OF LINGERING LIGHT SNOW IN THE FAR EAST EARLY SUNDAY EVENING...BUT DID NOT FEEL CONFIDENT ENOUGH TO ADD A POP AT THE MOMENT. H5 HEIGHTS RISE MONDAY WITH WARMER AIR RETURNING TO THE NORTHERN PLAINS FOR EARLY NEXT WEEK. THE WARMER AIR DOES NOT STAY IN PLACE FOR VERY LONG WITH ANOTHER COLD FRONT DROPPING ACROSS DAKOTAS WEDNESDAY INTO WEDNESDAY NIGHT. THE FRONT WILL ALSO BRING ANOTHER CHANCE OF PRECIPITATION...AGAIN MAINLY IN THE FORM OF SNOW. AT THE MOMENT...IT DOES NOT APPEAR TO BE A SIGNIFICANT PRECIPITATION MAKER. DRIER WEATHER TAKES HOLD AGAIN FOR THURSDAY AND FRIDAY. WARMER AIR RETURNS AGAIN FRIDAY INTO NEXT WEEKEND. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 642 AM CST SAT NOV 16 2013 BRIEF PATCHY FOG IS POSSIBLE AT KJMS EARLY THIS MORNING...OTHERWISE VFR WEATHER WILL PREVAIL THROUGH THE DAYLIGHT HOURS OF SATURDAY. HIGH AND MID LEVEL CLOUDS WILL INCREASE FROM THE NORTHWEST THROUGH THE DAY...AND LOWER AS MOISTURE INCREASES AFTER 16/18Z. A FEW SNOW FLURRIES ARE POSSIBLE FOR THE AREA AROUND KISN THIS MORNING...THEN ISOLATED RAIN SHOWERS SPREADING THROUGH KISN-KMOT-KDIK AFTER 16/22Z. SURFACE WINDS SATURDAY WILL BE 10 KNOTS OR LESS. THE RAIN SHOWERS WILL CHANGE TO SNOW AS LOW PRESSURE APPROACHES AFTER 17/03Z...WITH MVFR CIGS ALSO POSSIBLE. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...CK SHORT TERM...JPM LONG TERM...CK AVIATION...JPM
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
954 AM EST SAT NOV 16 2013 .SYNOPSIS... THE NEXT COLD FRONT IS EXPECTED TO PUSH THROUGH THE REGION SUNDAY NIGHT INTO EARLY MONDAY...FOLLOWED BY STRONG HIGH PRESSURE BUILDING OVER THE REGION THROUGH THE MIDDLE OF NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF MID MORNING...THE FCST APPEARS TO BE ON TRACK. SATELLITE IMAGERY SHOWS THE HIGH ELEVATIONS OF THE NC MTNS ALREADY POKING UP ABOVE THE LOW CLOUDS. A FEW HOLES IN THE OVERCAST ARE STARTING TO OPEN UP OVER THE PIEDMONT OF THE CAROLINAS...BUT THESE MIGHT FILL BACK IN WITH CLOUDS AT LEAST TEMPORARILY. THINK IT WILL TAKE A FEW MORE HOURS...UNTIL MIDDAY...BEFORE WHOLESALE SCATTERING OCCURS. TEMPS ARE IN GOOD SHAPE. PREVIOUS DISCUSSION... AS OF 245 AM EST SATURDAY...WIDESPREAD LOW CLOUDS AND AREAS OF FOG WILL GRADUALLY LIFT AND PARTIALLY BURN OFF THIS MORNING. SO FAR THE FOG HAS BEEN WELL SHORT OF ADVISORY CRITERIA. WITH ALL SITES REPORTING A CEILING AT THIS HOUR...IT WOULD APPEAR THAT ANY DENSE FOG THROUGH MID MORNING WILL BE ISOLATED. SCATTERED PATCHES OF RAIN CONTINUE ATTM OVER WRN NC...BUT A WEAKENING LOW LEVEL WIND FIELD AND NVA ALOFT SHOULD BRING THAT TO AN END IN A COUPLE HOURS. OTHERWISE IT WILL BE A QUIET WEATHER DAY AS HEIGHTS RISE OVER THE REGION AHEAD OF STRONG TROUGH DIGGING INTO THE CENTRAL HIGH PLAINS STATES. LOW LEVEL WINDS WILL INCREASE IN SPEED TONIGHT AHEAD OF THAT DEEPENING TROUGH. THE NAM H8 WINDS INCREASE TO AROUND 30 KTS. THE STRENGTHENING WINDS AND INCREASING LLVL WARM ADVECTION AS A THERMAL RIDGE MOVES IN FROM THE WEST WILL BE SUFFICIENT FOR ANOTHER ROUND OF UPSLOPE ENHANCED LIGHT RAIN AND DRIZZLE. THE BULK OF THE PCPN SHOULD BE CONFINED TO THE MOUNTAINS AND WRN FOOTHILLS. && .SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... AT 230 AM EST SATURDAY...AN UPPER RIDGE WILL BE OFF THE EAST COAST ON SATURDAY...WHILE AN UPPER TROUGH WILL BE OVER THE CENTER OF THE NATION. THE DEAMPLIFYING TROUGH AXIS WILL PROGRESS TO THE CENTRAL AND SOUTHERN APPALACHIANS BY BY MONDAY...MOVING OFF THE EAST COAST ON MONDAY NIGHT. SURFACE HIGH PRESSURE WIL WEAKEN ALONG THE EAST COAST ON SUNDAY... WHILE A COLD FRONT CROSSES THE MS RIVER VALLEY. MOIST ISENTROPIC UPGLIDE FLOW WILL PRECEDE THE FRONT ON SUNDAY AND SUNDAY NIGHT... HOWEVER LOW LEVEL UPSLOPE FLOW WILL WEAKEN AS WINDS VEER AND BECOME PARALLEL TO THE BLUE RIDGE. FRONTAL PASSAGE OVER OUR AREA IS EXPECTED TO OCCUR LATE SUNDAY NIGHT AND EARLY MONDAY. WHILE BOTH THE NAM AND GFS SHOW SHEAR CROSSING THE AREA WITH THE FRONT...NAM CAPE IS MARGINAL...AND GFS CAPE MUCH WEAKER. THE SITUATION WILL NEED TO BE MONITORED FOR THE POSSIBILITY OF A LOW CAPE...HIGH SHEAR ENVIRONMENT. PRECIPITATION IS NOT EXPECTED TO BE EXCESSIVE...WITH PERHAPS A BIT MORE THAN ONE INCH OF RAINFALL ALONG THE SOUTH FACING BLUE RIDGE ESCARPMENT. TEMPERATURES WILL WARM ABOVE NORMAL AHEAD OF THE FRONT...WITH A REDUCED DIURNAL RANGE IN CLOUDS AND PRECIPITATION. TEMPERATURES WILL WARM EVEN FURTHER ABOVE NORMAL MONDAY IN DOWNSLOPE FLOW BEHIND THE FRONT....BUT WILL FALL BELOW NORMAL MONDAY NIGHT IN COLD ADVECTION WITH WINDS DIMINISHING AND VEERING. && .LONG TERM /TUESDAY THROUGH FRIDAY/... AS OF 155 AM EST SATURDAY...TUESDAY THROUGH FRIDAY NIGHT...MEDIUM RANGE MODELS SHOW HIGH PRESSURE CENTERED OVER ILLINOIS AT 12Z TUESDAY WITH PRESSURE GRADIENT EASING OVER THE CAROLINAS. BY 00Z WED THE CENTER OF THE HIGH IS OVER THE EASTERN GREAT LAKES WITH LOW LEVEL WIND FLOW FOR OUR AREA BEING GENERALLY NE. AS THIS HIGH MOVES OFF THE NEW ENGLAND COAST THURSDAY AFTERNOON...THE WIND FLOW BECOMES MORE EAST TO SE AND TEMPS RISE A BIT FROM JANUARY TYPE TEMPS TO JUST A FEW DEGREES BELOW NORMAL ON FRIDAY. THE GFS HAS A SURFACE LOW FORMING OVER EAST TEXAS FRIDAY NIGHT AND MOVING NE WHILE THE ECMWF HAS A LESS VIGOROUS TROUGH AND SURFACE DEVELOPMENT. BOTH OF THESE MODELS HAVE AT LEAST SOME LIGHT PRECIP MOVING INTO THE WESTERN NC MTNS BY LATE FRIDAY NIGHT. THEREFORE...I HAVE INTRODUCED SLIGHT POPS FOR THAT AREA IN THE EXTRA PERIOD OF FRIDAY NIGHT. && .AVIATION /15Z SATURDAY THROUGH WEDNESDAY/... AT KCLT...SKIES HAVE ACTUALLY CLEARED ABOUT 20 MILES TO THE SOUTHEAST OF THE AIRFIELD. HOWEVER...THE LLVL FLOW IS WEAKLY OUT OF THE SOUTHWEST AND CIGS BETWEEN 005-007 SHOULD LAST THROUGH ABOUT 15 UTC. THE NAM MODEL SOUNDINGS IMPLY CONDITIONS COULD IMPROVE EARLIER...THE RAP LATER. WITH THE VERY LIGHT LLVL WINDS AND FAIRLY WEAK INVERSION...I DON/T SEE THE IFR LEVEL CIGS HANGING AROUND MUCH BEYOND 15 UTC...BUT I/M NOT TERRIBLY CONFIDENT ABOUT THIS. A PERIOD OF VFR CONDITIONS IS EXPECTED TO DEVELOP THIS AFTERNOON...WITH STRATUS RETURNING AGAIN TONIGHT. IN FACT...WITH A STRONGER WIND FIELD AND BETTER WARM ADVECTION...I THINK THE CHANCES OF AN IFR DECK ARE PRETTY GOOD. ELSEWHERE...IFR CONDITIONS PREVAIL ACROSS THE REGION THIS MORNING. EXPECTING CIGS TO HOLD GENERALLY BETWEEN 007-010 OVER THE NEXT FEW HOURS. HOWEVER...THERE HAVE BEEN BREAKS IN THE IFR WITH AN MVFR DECK ABOVE THAT. ADDED A TEMPO GROUP TO ACCOUNT FOR THIS AT ALL SITES EXCEPT KAVL. VSBYS SHOULD GENERALLY BE IN THE MVFR RANGE AT THE UPSTATE SITES...AND A LITTLE LOWER IN NC. IT IS POSSIBLE THAT CONDITIONS WILL WORSEN AFTER SUNRISE WITH THE MOIST LOW LEVELS. THE LLVL WINDS LOOK TOO WEAK TO SUPPORT STRATUS...CAUSING ME TO BE CONCERNED ABOUT INCREASING AMOUNTS OF FOG AFTER 12 UTC. I DON/T SEE ANYTHING TO REALLY HANG MY HAT ON IN THIS REGARD...WHICH IS WHY THE TAFS SIMPLY REFLECT THE PREVAILING CONDITIONS FOR ANOTHER 3 HOURS OR SO. THERE SHOULD BE SOME IMPROVEMENT THIS AFTN WITH MANY AREAS SEEING VFR CIGS. LATER SAT NIGHT AS THE LLVL WINDS AND WARM ADVECTION INCREASE...CHANCES LOOK GOOD FOR AN IFR DECK. LIGHT RAIN IS ALSO POSSIBLE LATE TONIGHT...ESPECIALLY AROUND KAVL. OUTLOOK...THE APPROACH OF THE NEXT STRONG COLD FRONT WILL BRING INCREASING RAIN CHANCES AND LIKELY RESTRICTIONS ON SUNDAY INTO EARLY MONDAY. A RETURN TO MUCH DRIER WEATHER IS EXPECTED BY LATE MONDAY. CONFIDENCE TABLE... 15-21Z 21-03Z 03-09Z 09-15Z KCLT HIGH 93% HIGH 83% MED 79% MED 75% KGSP MED 76% HIGH 90% MED 79% MED 78% KAVL MED 65% HIGH 83% HIGH 94% HIGH 96% KHKY MED 79% HIGH 84% HIGH 97% HIGH 100% KGMU MED 77% HIGH 90% HIGH 81% HIGH 81% KAND MED 79% HIGH 83% MED 77% MED 78% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...DEO NEAR TERM...MCAVOY/PM SHORT TERM...JAT LONG TERM...DEO AVIATION...MCAVOY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
641 AM EST SAT NOV 16 2013 .SYNOPSIS... THE NEXT COLD FRONT IS EXPECTED TO PUSH THROUGH THE REGION SUNDAY NIGHT INTO EARLY MONDAY...FOLLOWED BY STRONG HIGH PRESSURE BUILDING OVER THE REGION THROUGH THE MIDDLE OF NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 615 AM EST SATURDAY...UPPED MIN TEMPS A FEW DEGREES AS WIDESPREAD LOW CLOUDS HAVE RESULTED IN NEAR STEADY TEMPS THE BEST SEVERAL HOURS. DEWPOINTS ARE ALSO A LITTLE HIGHER THAN WHAT WAS IN THE GRIDS AND THOSE HAVE BEEN BUMPED UP AS WELL. IT WILL BE INTERESTING TO SEE IF FOG BECOMES MORE WIDESPREAD AFTER SUNRISE. AS OF 245 AM EST SATURDAY...WIDESPREAD LOW CLOUDS AND AREAS OF FOG WILL GRADUALLY LIFT AND PARTIALLY BURN OFF THIS MORNING. SO FAR THE FOG HAS BEEN WELL SHORT OF ADVISORY CRITERIA. WITH ALL SITES REPORTING A CEILING AT THIS HOUR...IT WOULD APPEAR THAT ANY DENSE FOG THROUGH MID MORNING WILL BE ISOLATED. SCATTERED PATCHES OF RAIN CONTINUE ATTM OVER WRN NC...BUT A WEAKENING LOW LEVEL WIND FIELD AND NVA ALOFT SHOULD BRING THAT TO AN END IN A COUPLE HOURS. OTHERWISE IT WILL BE A QUIET WEATHER DAY AS HEIGHTS RISE OVER THE REGION AHEAD OF STRONG TROUGH DIGGING INTO THE CENTRAL HIGH PLAINS STATES. LOW LEVEL WINDS WILL INCREASE IN SPEED TONIGHT AHEAD OF THAT DEEPENING TROUGH. THE NAM H8 WINDS INCREASE TO AROUND 30 KTS. THE STRENGTHENING WINDS AND INCREASING LLVL WARM ADVECTION AS A THERMAL RIDGE MOVES IN FROM THE WEST WILL BE SUFFICIENT FOR ANOTHER ROUND OF UPSLOPE ENHANCED LIGHT RAIN AND DRIZZLE. THE BULK OF THE PCPN SHOULD BE CONFINED TO THE MOUNTAINS AND WRN FOOTHILLS. && .SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... AT 230 AM EST SATURDAY...AN UPPER RIDGE WILL BE OFF THE EAST COAST ON SATURDAY...WHILE AN UPPER TROUGH WILL BE OVER THE CENTER OF THE NATION. THE DEAMPLIFYING TROUGH AXIS WILL PROGRESS TO THE CENTRAL AND SOUTHERN APPALACHIANS BY BY MONDAY...MOVING OFF THE EAST COAST ON MONDAY NIGHT. SURFACE HIGH PRESSURE WIL WEAKEN ALONG THE EAST COAST ON SUNDAY... WHILE A COLD FRONT CROSSES THE MS RIVER VALLEY. MOIST ISENTROPIC UPGLIDE FLOW WILL PRECEDE THE FRONT ON SUNDAY AND SUNDAY NIGHT... HOWEVER LOW LEVEL UPSLOPE FLOW WILL WEAKEN AS WINDS VEER AND BECOME PARALLEL TO THE BLUE RIDGE. FRONTAL PASSAGE OVER OUR AREA IS EXPECTED TO OCCUR LATE SUNDAY NIGHT AND EARLY MONDAY. WHILE BOTH THE NAM AND GFS SHOW SHEAR CROSSING THE AREA WITH THE FRONT...NAM CAPE IS MARGINAL...AND GFS CAPE MUCH WEAKER. THE SITUATION WILL NEED TO BE MONITORED FOR THE POSSIBILITY OF A LOW CAPE...HIGH SHEAR ENVIRONMENT. PRECIPITATION IS NOT EXPECTED TO BE EXCESSIVE...WITH PERHAPS A BIT MORE THAN ONE INCH OF RAINFALL ALONG THE SOUTH FACING BLUE RIDGE ESCARPMENT. TEMPERATURES WILL WARM ABOVE NORMAL AHEAD OF THE FRONT...WITH A REDUCED DIURNAL RANGE IN CLOUDS AND PRECIPITATION. TEMPERATURES WILL WARM EVEN FURTHER ABOVE NORMAL MONDAY IN DOWNSLOPE FLOW BEHIND THE FRONT....BUT WILL FALL BELOW NORMAL MONDAY NIGHT IN COLD ADVECTION WITH WINDS DIMINISHING AND VEERING. && .LONG TERM /TUESDAY THROUGH FRIDAY/... AS OF 155 AM EST SATURDAY...TUESDAY THROUGH FRIDAY NIGHT...MEDIUM RANGE MODELS SHOW HIGH PRESSURE CENTERED OVER ILLINOIS AT 12Z TUESDAY WITH PRESSURE GRADIENT EASING OVER THE CAROLINAS. BY 00Z WED THE CENTER OF THE HIGH IS OVER THE EASTERN GREAT LAKES WITH LOW LEVEL WIND FLOW FOR OUR AREA BEING GENERALLY NE. AS THIS HIGH MOVES OFF THE NEW ENGLAND COAST THURSDAY AFTERNOON...THE WIND FLOW BECOMES MORE EAST TO SE AND TEMPS RISE A BIT FROM JANUARY TYPE TEMPS TO JUST A FEW DEGREES BELOW NORMAL ON FRIDAY. THE GFS HAS A SURFACE LOW FORMING OVER EAST TEXAS FRIDAY NIGHT AND MOVING NE WHILE THE ECMWF HAS A LESS VIGOROUS TROUGH AND SURFACE DEVELOPMENT. BOTH OF THESE MODELS HAVE AT LEAST SOME LIGHT PRECIP MOVING INTO THE WESTERN NC MTNS BY LATE FRIDAY NIGHT. THEREFORE...I HAVE INTRODUCED SLIGHT POPS FOR THAT AREA IN THE EXTRA PERIOD OF FRIDAY NIGHT. && .AVIATION /12Z SATURDAY THROUGH WEDNESDAY/... AT KCLT...SKIES HAVE ACTUALLY CLEARED ABOUT 20 MILES TO THE SOUTHEAST OF THE AIRFIELD. HOWEVER...THE LLVL FLOW IS WEAKLY OUT OF THE SOUTHWEST AND CIGS BETWEEN 005-007 SHOULD LAST THROUGH ABOUT 15 UTC. THE NAM MODEL SOUNDINGS IMPLY CONDITIONS COULD IMPROVE EARLIER...THE RAP LATER. WITH THE VERY LIGHT LLVL WINDS AND FAIRLY WEAK INVERSION...I DON/T SEE THE IFR LEVEL CIGS HANGING AROUND MUCH BEYOND 15 UTC...BUT I/M NOT TERRIBLY CONFIDENT ABOUT THIS. A PERIOD OF VFR CONDITIONS IS EXPECTED TO DEVELOP THIS AFTERNOON...WITH STRATUS RETURNING AGAIN TONIGHT. IN FACT...WITH A STRONGER WIND FIELD AND BETTER WARM ADVECTION...I THINK THE CHANCES OF AN IFR DECK ARE PRETTY GOOD. ELSEWHERE...IFR CONDITIONS PREVAIL ACROSS THE REGION THIS MORNING. EXPECTING CIGS TO HOLD GENERALLY BETWEEN 007-010 OVER THE NEXT FEW HOURS. HOWEVER...THERE HAVE BEEN BREAKS IN THE IFR WITH AN MVFR DECK ABOVE THAT. ADDED A TEMPO GROUP TO ACCOUNT FOR THIS AT ALL SITES EXCEPT KAVL. VSBYS SHOULD GENERALLY BE IN THE MVFR RANGE AT THE UPSTATE SITES...AND A LITTLE LOWER IN NC. IT IS POSSIBLE THAT CONDITIONS WILL WORSEN AFTER SUNRISE WITH THE MOIST LOW LEVELS. THE LLVL WINDS LOOK TOO WEAK TO SUPPORT STRATUS...CAUSING ME TO BE CONCERNED ABOUT INCREASING AMOUNTS OF FOG AFTER 12 UTC. I DON/T SEE ANYTHING TO REALLY HANG MY HAT ON IN THIS REGARD...WHICH IS WHY THE TAFS SIMPLY REFLECT THE PREVAILING CONDITIONS FOR ANOTHER 3 HOURS OR SO. THERE SHOULD BE SOME IMPROVEMENT THIS AFTN WITH MANY AREAS SEEING VFR CIGS. LATER SAT NIGHT AS THE LLVL WINDS AND WARM ADVECTION INCREASE...CHANCES LOOK GOOD FOR AN IFR DECK. LIGHT RAIN IS ALSO POSSIBLE LATE TONIGHT...ESPECIALLY AROUND KAVL. OUTLOOK...THE APPROACH OF THE NEXT STRONG COLD FRONT WILL BRING INCREASING RAIN CHANCES AND LIKELY RESTRICTIONS ON SUNDAY INTO EARLY MONDAY. A RETURN TO MUCH DRIER WEATHER IS EXPECTED BY LATE MONDAY. CONFIDENCE TABLE... 11-17Z 17-23Z 23-05Z 05-11Z KCLT MED 74% HIGH 92% HIGH 87% MED 73% KGSP MED 62% HIGH 88% MED 71% HIGH 82% KAVL MED 66% MED 79% MED 75% HIGH 93% KHKY LOW 55% HIGH 86% HIGH 83% HIGH 95% KGMU MED 61% HIGH 88% MED 68% HIGH 80% KAND LOW 55% HIGH 85% MED 71% MED 73% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...DEO NEAR TERM...MCAVOY SHORT TERM...JAT LONG TERM...DEO AVIATION...MCAVOY
SEE BELOW FOR AN UPDATED AVIATION FORECAST DISCUSSION.

&& .PREVIOUS DISCUSSION... .SHORT TERM...TODAY THROUGH MONDAY WEAK UPPER LEVEL DISTURBANCE DRIFTING NORTHEAST ACROSS THE AREA EARLY THIS MORNING. WEAK LIFT SLIDING THROUGH AND FOG SATELLITE SHOWING SOME TEXTURE TO THE MID LEVEL DECK MOVING NORTHEAST THROUGH THE CWA. RADAR HAS SOME VERY LIGHT RETURNS WITHIN THE MID LEVEL DECK......MAYBE JUST A COUPLE SPRINKLES. MAIN THING TO WATCH TODAY IS THE SECONDARY WAVE WHICH IS A TAD FURTHER SOUTH...AND ITS EXPECTED DEVELOPMENT OF SHOWERS ACROSS SOUTHEAST SOUTH DAKOTA INTO MINNESOTA. EVEN THIS CLOSE TO EVENT TIME...MODELS STILL HAVING A TOUGH TIME DETERMINING PLACEMENT OF PRECIP AND THE HANDLING OF THE STRATUS DECK WELL TO THE SOUTH. NO SIGN OF STRATUS ANYWHERE NEAR THE CWA...WITH THINGS RIGHT NOW PUSHED WELL SOUTH INTO KANSAS AND MISSOURI. ALTHOUGH...MODELS STILL SUGGESTING SOME DEVELOPMENT SHORTLY AFTER 12Z. VERY LOW CONFIDENCE IN JUST HOW FAST STRATUS MAKES IT INTO SOUTHEAST SOUTH DAKOTA AND THE SOUTHEAST CWA. FOR RIGHT NOW HAVE CONSTRUCTED SKY GRIDS TO SHOW SOME INCREASE IN CLOUDS LATER THIS MORNING. FEEL THERE WILL BE AT LEAST SOME DEVELOPMENT OF STRATUS BY LATER TODAY. REMOVED DRIZZLE FROM THE FORECAST AS SOUNDINGS OVER THE SOUTHEAST CWA JUST DO NOT SUPPORT IT. NO DEEP MOISTURE LAYER DOWN LOW AT ALL. BETTER SIGNAL SHOWS UP CLOSE TO SIOUX FALLS AREA. WILL LEAVE IN 20 POPS ACROSS THE FAR EASTERN CWA TO SORT OF GO ALONG WITH WHAT THE HRRR AND ABR 4KM MODELS ARE SHOWING. AT THIS POINT...NOT REALLY BUYING INTO THE MORE QPF-HAPPY EC AND GFS WHICH HAS PRECIP BACK FURTHER WEST INTO THE JAMES VALLEY WITHIN A STRATUS DECK. ATTENTION THEN TURNS TO THE STRONGER UPPER LEVEL SHORTWAVE ENERGY MOVING ACROSS THE DAKOTAS LATE TONIGHT THROUGH SUNDAY. MODELS CONTINUE TO WARM THE LOWER LEVELS OF THE ATMOSPHERE AND HAVE INCREASED HIGHS ON SUNDAY. NOW IT APPEARS MOST OF TONIGHT WILL BE DRY WITH CHANCES MOVING INTO THE WESTERN CWA BY 12Z SUNDAY. LEFT PRECIP MOSTLY RAIN THOUGH AS THERMAL PROFILES STILL FAIRLY MILD THROUGH THE NIGHT. AROUND 12Z SUNDAY AND SHORTLY AFTER THE COLUMN BEGINS TO COOL ENOUGH TO SUPPORT MAINLY SNOWFALL DURING THE MORNING HOURS...BUT WARMING AGAIN DURING THE AFTERNOON. MODELS HAVING A TOUGH TIME WITH THIS SHORTWAVE ENERGY AS WELL IN REGARDS TO PRECIP PLACEMENT. OVERALL...A FAIRLY LOW CONFIDENCE FORECAST UNFORTUNATELY. BUT HAVING SAID THAT...IT DOES APPEAR THE BEST CHANCE FOR PRECIP IN THE SHORT TERM WILL BE WITH WHATEVER MATERIALIZES WITHIN THE UPPER LEVEL SHORTWAVE ENERGY LATER TONIGHT THROUGH SUNDAY. ALSO NEED TO MENTION THE WINDS ON SUNDAY AS THEY WILL GET RATHER GUSTY WITHIN A TIGHTENING PRESSURE GRADIENT. COULD BE LOOKING AT WIND ADVISORY SPEEDS OVER THE WESTERN CWA ON SUNDAY. WILL CONTINUE TO MONITOR. .LONG TERM...MONDAY NIGHT THROUGH FRIDAY SEEMS THE GLOBAL SPECTRAL MODELS ARE CONTINUING TO HAVE A TOUGH TIME RESOLVING FLOW PATTERN EVOLUTION AND SHORT-WAVE TIMING IN THE FARTHER OUT FORECAST TIME PERIODS. FOR THE PAST COUPLE OF MORNINGS THE GFS AND ECMWF HAVE BEEN HINTING AT THE DEVELOPMENT OF A PERIOD OF SPLIT FLOW IN THE OUT PERIODS. MODELS ARE KNOWN TO HAVE DIFFICULTIES RESOLVING FLOW PATTERN FEATURES IN THE SHORTER RANGE FORECAST PERIODS /CONSIDERABLY LOWER FORECAST CONFIDENCE/ WHEN A SPLIT FLOW PATTERN IS OCCURRING OR IMMINENT...LET ALONE THE LONGER RANGE FORECAST TIME-FRAME. SO IT WOULD BE SAFE TO SAY...FORECASTER CONFIDENCE IN LONGER RANGE SOLUTIONS IS LOWER THAN NORMAL. THE ECMWF STILL HAS A STRONG COLD FRONT WORKING THROUGH THE REGION BY THE MIDDLE OF NEXT WEEK. IT DOES NOT HAVE A BAND OF SNOW WORKING ACROSS THE CWA...THOUGH...FOR WEDNESDAY NIGHT. THAT FEATURE HAS SLOWED BY ABOUT 12 HOURS AND IS FURTHER SOUTH NOW ACROSS NEBRASKA. THE GFS COLD FRONTAL FEATURE STILL SEEMS TO LAG BEHIND THE ECMWF BY ABOUT 12 HOURS...WHILE THE GEM REMAINS APPX 12 HOURS FASTER THAN THE ECMWF. SO...WITH FRONTAL TIMING DIFFERENCES STILL ABOUNDING...AND PRECIPITATION TIMING/PLACEMENT FORECASTS STILL EVOLVING...SEEMS LIKE GOING AS DRY AS POSSIBLE FOR AS MUCH OF THE LONG TERM AS POSSIBLE IS A GOOD MOVE THIS MORNING. AT THIS POINT...THURSDAY STILL LOOKS LIKE THE COLDEST DAY OF THE EXTENDED...ALTHOUGH THAT WILL PROBABLY CHANGE BY TOMORROW MORNING...AS WELL. && .AVIATION... 12Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS VFR SHOULD PREVAIL TODAY AND TONIGHT AT KMBG...KPIR AND KABR. THERE MAY BE A COUPLE SPRINKLES OR FLURRIES AT KPIR AND KABR AND ALONG A LINE BETWEEN THESE TWO TERMINALS THROUGH ABOUT MID-DAY TODAY. BUT...THIS SHOULD NOT IMPACT CIGS OR VISBIES. KATY CONTINUES TO REMAIN THE CONCERN FOR SUB-VFR CONDITIONS. SURFACE TO TOP-OF-THE-BOUNDARY-LAYER MOISTURE CONTINUES TO INCREASE THIS MORNING ON LIGHT SOUTH WINDS. UPSTREAM FROM KATY...SITES ACROSS SERN SOUTH DAKOTA AND SWRN MINNESOTA ARE REPORTING IFR CIGS AND IN SOME CASES MVFR/IFR VISBIES. SEEMS INCREASINGLY PROBABLE THAT KATY WILL BE DOWN INTO SOME FORM OF SUB-VFR FLYING CONDITIONS WITHIN THE NEXT 3 TO 6 HOURS. THERE IS ALSO A CHANCE FOR SOME RAIN AT KATY MAINLY LATER THIS AFTERNOON FOR A FEW HOURS AS A LOW PRESSURE SYSTEM LIFTS NEWD ACROSS THE REGION. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. && $$ UPDATE...DORN SHORT TERM...TMT LONG TERM...DORN AVIATION...DORN WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
533 AM CST SAT NOV 16 2013 .DISCUSSION... SEE THE 12Z AVIATION DISCUSSION BELOW. 40 && .AVIATION... DIFFICULT FORECAST. MVFR TO IFR SHOULD IMPROVE SLOWLY THROUGH THE MID AND LATE MORNING. ISOLATED SHOWERS WERE DEVELOPING OVER THE GULF WATERS SOUTH OF FREEPORT...HOWEVER THE MODEL SOUNDINGS INDICATE A CAP WILL BE IN PLACE AND DO NOT EXPECT THESE TO BECOME MORE WIDESPREAD. AS THE CEILINGS LIFT...BREEZY CONDITIONS MAY DEVELOP THIS AFTERNOON. ANOTHER ROUND OF AT LEAST MVFR TONIGHT. 40 && .PREV DISCUSSION... /ISSUED 402 AM CST SAT NOV 16 2013/ DISCUSSION... PATCHY FOG...LOCALLY DENSE IN A FEW SPOTS...WILL PERSIST THROUGH MID MORNING BEFORE ERODING. DEEP MOISTURE REMAINS IN PLACE. NOT MUCH IN THE WAY OF A LOW LEVEL FOCUS AND UPPER LEVEL SUPPORT BUT THE MOISTURE LEVELS ARE SO HIGH THAT FEEL SOME SHOWERS WILL DEVELOP DURING THE DAY. BOTH THE RAP AND TEXAS TECH WRF SHOW SHOWERS DEVELOPING THIS AFTN SO WILL ADD 20 POPS BACK TO THE FCST. OVERNIGHT LOWS ON SUN MORNING WILL BE UNSEASONABLY WARM AND MINS WILL ONLY FALL INTO THE UPPER 60S. W-SW WINDS JUST OFF THE SURFACE COUPLED WITH THE WARM START SHOULD YIELD MAX TEMPS IN THE MID 80S. RECORD HIGH TEMPERATURES ARE POSSIBLE ON SUNDAY. FCST SOUNDINGS ON SUNDAY SHOW AN ERODING CAP AND PWATS BETWEEN 1.6 AND 1.8 INCHES SO WILL MAINTAIN 20 POPS ON SUNDAY. A COLD FRONT WILL CROSS SE TX ON MONDAY. GFS LOOKS A BIT FAST WITH THIS FEATURE AND PREFER THE SLOWER NAM/ECMWF SOLN. MSTR POOLS AHEAD OF THE BOUNDARY AND SCT SHRA/TSRA WILL BE POSSIBLE ALONG THE COAST AND PARTS OF THE SOUTHERN CWA. AM CARRYING CHC POPS FOR THE COAST ON MONDAY MORNING BUT FEEL THESE MIGHT BE A TAD LOW. MSTR LEVELS NEVER REALLY DROP OFF THIS WEEK AND AN UPPER LEVEL DISTURBANCE COULD BRING MORE SHOWERS ON TUESDAY AFTN. SW FLOW ALOFT ON THURSDAY WILL BRING A DISTURBANCE ACROSS SE TX. THIS FEATURE COUPLED WITH PWATS AROUND 1.6 INCHES SHOULD AGAIN YIELD MORE PRECIP. MSTR ON THE BACKSIDE OF A RETREATING SURFACE RIDGE WILL CONTINUE TO DRAW DEEPER MSTR INTO SE TX THU/FRI. A COLD FRONT WILL CROSS SE TX ON FRI AND RAIN CHANCES WILL CONTINUE. A DEEP UPPER LEVEL LOW WILL REMAIN WEST OF THE REGION THROUGH NEXT WEEKEND. ISENTROPIC UPGLIDE WILL BE MAXIMIZED WITH NNE SFC WINDS BEING OVERRUN BY SW WINDS ALOFT. NEXT WEEKEND LOOKS RAINY AND KIND OF RAW. MAX TEMPS WILL STRUGGLE TO REACH 50 DEGREES IF THE ECMWF VERIFIES. LEANED TOWARD THE ECMWF NEXT FRI-SUN BUT MODELS DIFFER WITH TIMING AND RUN TO RUN CONSISTENCY HAS BEEN POOR. 43 CLIMATE... RECORD HIGH TEMPERATURES ARE POSSIBLE ON SUNDAY. RECORDS FOR SUNDAY NOV 17TH ARE THE FOLLOWING: CURRENT RECORDS FORECAST VALUES IAH 84 - 1985 86 CLL 85 - 1921 86 MARINE... LONG PERIOD SWELLS WERE OCCURRING AT BUOY 42019. MAY NEED TO UPGRADE TO A SMALL CRAFT ADVISORY IF THESE CONTINUE AND WILL UPDATE IF NEEDED. OTHERWISE...WINDS WILL GRADUALLY DECREASE LATER TODAY AND TONIGHT AS A COLD FRONT MOVES TOWARD THE COAST. THE FRONT IS EXPECTED TO PUSH OFF THE COAST MONDAY MORNING WITH INITIAL POST FRONTAL WINDS OUT OF THE NORTH. THE MODELS ARE CONSISTENT WITH MODERATE TO STRONG NORTHEAST WINDS DEVELOP MONDAY NIGHT AND TUESDAY. AS HIGH PRESSURE MOVES ACROSS THE LOWER MISSISSIPPI VALLEY INTO THE EASTERN SEABOARD...EXPECT SOUTHEAST WINDS TO DEVELOP BY WEDNESDAY. 40 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 81 71 86 61 74 / 20 20 20 10 10 HOUSTON (IAH) 81 72 86 66 77 / 20 20 20 20 20 GALVESTON (GLS) 77 70 78 69 74 / 20 20 20 30 20 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT ADVISORY UNTIL 9 AM CST THIS MORNING FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM. && $$ DISCUSSION...43 AVIATION/MARINE...40
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
243 PM CST SAT NOV 16 2013 .DISCUSSION... 1230 PM CST ONLY SMALL CHANGES MADE TO THIS AFTERNOON FORECAST. SHOWER COVERAGE WILL FURTHER INCREASE AHEAD OF THE WELL-DEFINED SHORT WAVE TROUGH LIFTING NORTHEAST FROM THE NE/IA BORDER. THE MOISTURE TRANSPORT NOSE ALONG WITH ELEVATED STEEP LAPSE RATES SEEN ON 12Z REGIONAL SOUNDINGS WILL CONTINUE TO ADVECT OVER THE AREA SUPPORTING AND REPLENISHING THIS ACTIVITY INTO EARLY EVE. SEVERE POTENTIAL REMAINS VERY LOW WITH THIS. TEMPERATURES SHOULD CONTINUE TO WARM ESPECIALLY OUTSIDE OF THE SHOWERS...JUST SIMPLY BY PURE ADVECTION. PRONOUNCED REGIONAL SEVERE THREAT CONTINUES FOR LATE TONIGHT INTO SUNDAY AFTERNOON. NEW SPC MODERATE RISK DOES INCLUDE A LARGER PORTION OF THE FORECAST AREA...INCLUDING ALL OF CHICAGOLAND. UPDATED DISCUSSION ON THIS WILL BE POSTED BY 300 PM. MTF //PREV DISCUSSION... 815 AM CST FORECAST UPDATED TO ADD DRIZZLE IN THROUGH THIS MORNING. THE LOW-LEVEL MOISTURE SURGE CONTINUES TO RETURN OVER THE AREA. ISENTROPIC ASCENT ON THE RAP ANALYSIS OF 285K AND 290K SURFACES HAS RAPIDLY SATURATED AND LOOKS TO BE THE ROOT OF THIS. EVEN ON THE 12Z ILX RAOB...THE PROFILE WAS VERY SUGGESTIVE OF DRIZZLE. THIS COULD CONTINUE INTO THIS AFTERNOON BASED ON THE EXTENT OF UPSTREAM OBS ACROSS CENTRAL AND SOUTHERN IL. SOUTH WINDS CONTINUE TO BRING WARM AIR ADVECTION SO TEMPERATURES WILL INCH UPWARD. THE CHANCE FOR TRUE SHOWERS AND POSSIBLY SOME STORMS TODAY STILL LOOKS TO ARRIVE WITH A SHORT WAVE ACROSS THE WESTERN FORECAST AREA BY EARLY AFTERNOON AND SPREADING EAST FROM THERE. MTF //PREV DISCUSSION... 333 AM...FORECAST FOCUS REMAINS POTENTIAL SEVERE WEATHER OUTBREAK ACROSS THE SOUTHERN LAKES AND OHIO VALLEY ON SUNDAY. IN THE SHORT TERM...LOW CLOUDS HAVE STREAMED NORTH ACROSS THE AREA SIGNALING THE BEGINNING OF A SURGE OF LOW LEVEL MOISTURE. DEWPOINTS SLOWLY CREEPING INTO THE LOWER 40S EARLY THIS MORNING WILL CONTINUE TO RISE INTO THE LOWER/MID 50S THIS AFTERNOON...UPPER 50S TONIGHT AND LIKELY POOL IN THE LOWER TO PERHAPS MID 60S JUST AHEAD OF THE COLD FRONT SUNDAY MORNING. LOW PRESSURE OVER NEBRASKA WILL LIFT NORTH TO MINNESOTA BY THIS EVENING AND AS IT DOES...AN UPPER LEVEL WAVE WILL MOVE ACROSS THE AREA THIS AFTERNOON INTO THIS EVENING. MUCH OF THE EASTERN HALF OR TWO THIRDS WILL LIKELY REMAIN DRY THIS MORNING WITH PRECIP SPREADING ACROSS THE WESTERN CWA BY LATE MORNING. HAVE INCLUDED JUST A CHANCE OF THUNDERSTORMS WITH THE STRONGER/CONVECTIVE ELEMENTS BUT CONFIDENCE REGARDING HOW WIDESPREAD LIGHTNING/THUNDER WILL BECOME IS SOMEWHAT LOW AND THUNDER COVERAGE MAY NEED TO BE INCREASED BASED ON SHORT TERM TRENDS ONCE PRECIP DEVELOPS/ARRIVES. THIS ACTIVITY SHOULD MOVE NORTHEAST OF THE AREA BY MID/LATE EVENING WITH A POSSIBLE LULL IN ACTIVITY INTO THE EARLY MORNING HOURS. NOT EXPECTING ANY OF THE THUNDERSTORMS DURING THIS FIRST WAVE TO BE SEVERE. SOME COULD PRODUCE STRONG/GUSTY WINDS AS WELL AS HEAVY RAIN. THOUGH STORM MOTION SHOULD BE SUFFICIENTLY FAST TO PREVENT A LONG DURATION HEAVY RAIN IN ANY ONE LOCATION. RAINFALL AMOUNTS WITH THIS WAVE APPEAR TO BE IN THE 0.5 TO 0.75 RANGE. DESPITE MAINLY CLOUDY SKIES TODAY AND THEN PRECIP THIS AFTERNOON...WITH THE NOTED SURGE IN LOW LEVEL MOISTURE...TEMPS WILL CONTINUE TO CLIMB THROUGH THE DAY WITH CURRENT TEMPS ALREADY IN THE LOWER 50S ACROSS SOUTHERN IL. THUS...HIGHS IN THE UPPER 50S TO LOWER 60S LOOK ON TRACK AND MUCH OF THE SOUTHERN THIRD/HALF OF THE CWA MAY NOT SEE PRECIP UNTIL LATE THIS AFTERNOON AND IF ANY BREAKS DEVELOP...THIS WILL AID TEMPS FURTHER. AS PRECIP ENDS THIS EVENING...POSSIBLE FOR SOME LOCATIONS...ESPECIALLY NORTHERN CWA...TO CONTINUE TO WARM WITH HIGHS BEING REACHED IN THE EVENING. A SECOND LOW THEN DEVELOPS OVER EASTERN COLORADO TONIGHT AND QUICKLY SHIFTS EAST TO IOWA BY SUNDAY MORNING...THEN RAPIDLY DEEPENS AS IT ABSORBS THE FIRST LOW OVER MINNESOTA...AND REACHES LAKE SUPERIOR BY SUNDAY EVENING. A STRONG COLD FRONT WILL RACE ACROSS THE CWA FROM MID/LATE SUNDAY MORNING THROUGH EARLY/MID SUNDAY AFTERNOON. ANOTHER WAVE OF THUNDERSTORMS IS POSSIBLE IN THE EARLY MORNING HOURS OF SUNDAY AHEAD OF THIS SECOND LOW... DEVELOPING OVER EASTERN IOWA AND NORTHWEST IL THEN MOVING INTO SOUTHERN WI...MOSTLY LIKELY BY SUNRISE. AT THE SAME TIME... ADDITIONAL THUNDERSTORMS COULD BE DEVELOPING AHEAD OF THE COLD FRONT ACROSS PARTS OF IOWA/MISSOURI. ANY OF THESE THUNDERSTORMS OVERNIGHT INTO EARLY SUNDAY MORNING COULD BECOME SEVERE. BUT TO WHAT EXTENT AND HOW WIDESPREAD ANY SEVERE WEATHER WOULD BECOME IS UNCERTAIN. HOWEVER...WITH SUCH WARM/MOIST LOW LEVELS...A DEEPENING SURFACE LOW AND WHAT COULD END UP BEING A WARM FRONTAL BOUNDARY ACROSS THE NORTHERN CWA...THE THREAT OF A TORNADO WITH ANY STRONG STORMS CAN/T BE RULED OUT. ANOTHER BRIEF LULL IS EXPECTED SUNDAY MORNING BEFORE WHAT APPEARS LIKE IT COULD BE THE BEGINNING OF A WIDESPREAD SEVERE WEATHER OUTBREAK DEVELOPS. WINDS THROUGH THE ENTIRE COLUMN REMAIN VERY IMPRESSIVE WITH 50 KNOTS AS LOW AS 900MB SUNDAY MORNING. AS NOTED...WHILE THE WARM/MOIST CONDITIONS WILL HELP/AID STORMS STAYING SURFACE BASED...EXPECT QUITE A BIT OF CLOUD COVER...AND WHILE HAVE TRIED TO SHOW SOME PARTLY/MOSTLY CLOUDY CONDITIONS AT LEAST ACROSS THE SOUTHEAST CWA SUNDAY MORNING...ITS POSSIBLE OVERCAST CONDITIONS WILL PERSIST UNTIL FROPA. ADDITIONAL UNCERTAINTY REMAINS WITH WHERE/WHEN THUNDERSTORMS WILL DEVELOP... JUST WEST OF THE CWA...OVER THE CWA...EASTERN CWA/NORTHWEST INDIANA. ENTIRE CWA IS NOW INCLUDED IN SLIGHT RISK PER THIS MORNING/S SPC DAY2 OUTLOOK WITH MODERATE RISK EAST OF THE I-55/I-57 CORRIDOR. POTENTIAL IS CERTAINLY HIGHER OVER THE EASTERN CWA BUT EVEN FROM THIS DISTANCE WILL BE INCLUDING SEVERE MENTION/DAMAGING WINDS IN THE ZONES/GRIDS. THUNDERSTORMS WILL BE ENDING FROM WEST TO EAST DURING THE MID/LATE AFTERNOON AND ALSO ATTEMPTED TO INCLUDE THIS TIMING IN THE GRIDS. THE THREAT OF A TORNADO OR TWO WILL REMAIN SUNDAY BUT DAMAGING WINDS APPEAR TO BE THE PRIMARY SEVERE WEATHER THREAT. DESPITE PRECIPITABLE WATER VALUES ONLY AROUND AN INCH...EXPECT VERY EFFICIENT RAIN PRODUCTION WITH ANOTHER 0.5-0.75 INCHES POSSIBLE...ALTHOUGH PERHAPS MORE LOCALIZED DEPENDING ON CONVECTIVE COVERAGE. STRONG WINDS FROM THE SOUTH WILL DEVELOP TODAY WITH GUSTS INTO THE 30-35 MPH RANGE POSSIBLE. STILL APPEARS THERE COULD BE A 3-6 HOUR WINDOW THIS EVENING OF GUSTS 40+ MPH BEFORE WINDS DIMINISH SOME OVERNIGHT...WHILE CLOSE TO WIND ADVISORY CRITERIA...NOT SURE IT WILL BE REACHED AND NO HEADLINES THROUGH TONIGHT. BY SUNDAY... LOW LEVEL WINDS ARE WELL INTO ADVISORY CRITERIA AND SOME OF THIS WILL LIKELY MIX TO THE SURFACE ESPECIALLY JUST BEHIND THE STORMS/ COLD FRONT AS COLD ADVECTION IS AIDED BY LARGE PRESSURE RISES. THIS IS THIRD PERIOD AND A BIT EARLY FOR AN ADVISORY AND LATER SHIFTS WILL NEED TO ASSESS WIND POTENTIAL/HEADLINES FOR SUNDAY. HAVE CONTINUED INCREASING HIGH TEMPS FOR SUNDAY WITH MID 60S NORTH TO UPPER 60S FROM I-55 SOUTH AND ITS QUITE POSSIBLE SOME AREAS MAY SEE TEMPS TAG 70 AHEAD OF THE FRONT...ESPECIALLY WITH ANY BREAKS IN THE OVERCAST AS 850MB TEMPS ARE NOW EXPECTED TO BE IN THE +12C TO +15C RANGE. WRAP AROUND SHOWERS WILL BE POSSIBLE SUNDAY EVENING BUT SHOULD BE ENDING FAIRLY QUICKLY WITH CLEARING SKIES OVERNIGHT AS HIGH PRESSURE BUILDS INTO THE REGION MONDAY AFTERNOON/MONDAY NIGHT AND THIS HIGH IS MOVING FASTER THAN PREVIOUS MODELS HAD SUGGESTED. WHILE IT WILL TURN MUCH COLDER MONDAY NIGHT WITH LOWS IN THE 30S... MONDAY MAY END UP BEING MAINLY SUNNY WITH DIMINISHING WINDS IN THE AFTERNOON AND TEMPS REBOUNDING BACK INTO THE MID 40S. STILL WILL FEEL MUCH COLDER COMPARED TO SUNDAY...BUT THE TREND IS SLIGHTLY WARMER. HAVE CONTINUED THE WARMING TREND TUESDAY THROUGH THURSDAY AS WINDS TURN SOUTHERLY SOONER ON THE BACK SIDE OF THE DEPARTING HIGH. ALSO NOW APPEARS THE CHANCE OF SHOWERS WILL ARRIVE SOONER...PERHAPS AS EARLY AS LATE WEDNESDAY BUT CERTAINLY WEDNESDAY NIGHT INTO THURSDAY. WARMING TEMPS DURING THIS PERIOD WITH SOUTHERLY FLOW SHOULD KEEP PRECIP MAINLY LIQUID. A COLD FRONT THEN MOVES SOUTH THURSDAY NIGHT AND FRIDAY WITH THE ECMWF MUCH COLDER THAN THE GFS AND HAVE LOWERED TEMPS A FEW DEGREES DURING THIS TIME PERIOD AND WHILE ITS STILL SEVERAL DAYS AWAY...POTENTIAL FOR SOME FROZEN PRECIP EXISTS LATER FRIDAY/FRIDAY NIGHT...DEPENDING ON SPEED OF FRONT AND END TIME OF PRECIP. CMS && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 20Z... * IFR CIGS THIS AFTERNOON AND POTENTIALLY THROUGH TONIGHT. * SHRA WITH GRADUALLY INCREASING CHANCES FOR THUNDER THROUGH EARLY EVE. * SOUTH WINDS GUSTING TO AROUND 30 KT AT TIMES THROUGH THIS EVE...THEN TURNING SOUTHWEST AND BECOMING EVEN MORE GUSTY ON SUNDAY AFTERNOON. * LOW LEVEL WIND SHEAR POSSIBLE AS WINDS NEAR 1500 FT INCREASE TO 50 KT OR STRONGER. * TSRA CHANCES INCREASING AROUND DAYBREAK WITH GUSTY SEVERE STORM POTENTIAL THIS MORNING AND EARLY AFTERNOON. //DISCUSSION...UPDATED 18Z... INITIAL LOW PRESSURE MOVING NORTHWARD INTO MN CONTINUES TO INCREASE SOUTHERLY WINDS ACROSS THE AREA...AND AS AN EVEN MORE POTENT LOW PRESSURE DEVELOPS ON SUNDAY THE SOUTH WINDS WILL REALLY RAMP UP. SOUTHERLY GUSTS TO 30 KT OR EVEN SLIGHTLY HIGHER MAY BE SEEN THIS AFTERNOON. SHOWERS WITH EMBEDDED SCATTERED THUNDER WILL INCREASE IN COVERAGE THROUGH LATE AFTERNOON WITH THIS INITIAL LOW PRESSURE. THERE PROBABLY WILL BE A SLIGHT DIMINISHING IN COVERAGE THEN THROUGH THE MID TO LATE EVE AS THIS INITIAL MOISTURE SURGE PASSES. BUT AS INFLUENCE OF THE SECOND WEATHER SYSTEM BEGINS TO OVERSPREAD THE AREA...SCATTERED STORMS ARE LIKELY TO DEVELOP OVERNIGHT INTO SUNDAY MORNING THAT WILL ADVANCING NORTHWARD. THUNDER POTENTIAL WILL MAXIMIZE DURING THE LATE MORNING THROUGH MID AFTERNOON FOR THE CHICAGO AREA TAF SITES. SOME OF THESE COULD BE SEVERE GIVEN THE POTENT WIND FIELD AND SURPRISING INSTABILITY WITHIN THIS SYSTEM FOR THIS TIME OF YEAR. WINDS AROUND AND UNDER THESE STORMS WILL BE ESPECIALLY GUSTY...BUT EVEN THE PREVAILING WINDS WILL BE VERY GUSTY BY AFTERNOON...WITH GUSTS OF 35KT+. MTF //ORD AND MDW CONFIDENCE...UPDATED 20Z... * MEDIUM TO HIGH CONFIDENCE IN IFR CIGS THROUGH EARLY EVE. * HIGH CONFIDENCE IN SHRA THROUGH EARLY THIS EVE. * HIGH CONFIDENCE IN WIND DIRECTION...SPEEDS...AND GUSTS THROUGH 18Z SUNDAY...MEDIUM CONFIDENCE AFTER. * HIGH CONFIDENCE IN 50-60KT SW WINDS IN THE 1500-3000FT LAYER THIS EVE. * MEDIUM CONFIDENCE IN TSRA TIMING THROUGHOUT THE TAF. HIGH CONFIDENCE THAT IF STRONG TO SEVERE STORMS OCCUR AT THE AIRPORTS THEY WOULD BE BE AFTER 10Z...AND MOST PROBABLE 17Z-21Z. //OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z... SUNDAY NIGHT...BREEZY WEST WINDS DIMINISHING LATE. MONDAY THROUGH WEDNESDAY...VFR. THURSDAY AND FRIDAY...SLIGHT CHANCE SHRA DURING THE DAY AND RASN AT NIGHT. MAINLY VFR. MDB && .MARINE... 215 PM CST A STRONG STORM SYSTEM WILL IMPACT THE GREAT LAKES REGION OVER THE WEEKEND BRINGING PERIODS OF GALES WITH STORM FORCE WINDS A POSSIBILITY ON THE BACK END OF THE SYSTEM. BROAD AREA OF LOW PRESSURE IS BEGINNING TO CONSOLIDATE OVER THE NORTHERN PLAINS TODAY...BUT WILL SIGNIFICANTLY DEEPEN OVER WISCONSIN EARLY SUNDAY AFTERNOON...THEN CONTINUE TO DEEPEN AS IT MOVES ACROSS NORTHERN LAKE MICHIGAN SUNDAY EVENING. SOUTHERLY GALES WILL CONTINUE THROUGH THE OVERNIGHT HOURS INTO EARLY SUNDAY. THESE WINDS WILL TRANSPORT MOIST AIR NORTH OVER THE WATERS WHICH IS EXPECTED TO LEAD TO AREAS OF FOG DEVELOPMENT. IT IS UNCERTAIN HOW WIDESPREAD OR DENSE THE FOG WILL BE...BUT A FOG ADVISORY IS NOT OUT OF THE REALM OF POSSIBILITY. WINDS ARE EXPECTED TO EASE SLIGHTLY BELOW GALES DURING PORTIONS OF THE DAY SUNDAY...ESPECIALLY THE NORTHERN HALF OF THE LAKE WHERE THE GRADIENT WILL WEAKEN NEAR THE LOW CENTER. AFTER THE LOW AND ATTENDANT COLD FRONT PUSH EAST OF THE LAKE SUNDAY EVENING...WINDS WILL TURN WESTERLY AND QUICKLY RAMP BACK UP TO STRONG GALES OF 40 TO 45 KT...WITH OCCASIONAL STORM FORCE GUSTS STILL A POSSIBILITY. WINDS WILL SLOWLY TAPER MONDAY AS A RIDGE OF HIGH PRESSURE BUILDS ACROSS THE MISSISSIPPI VALLEY...AND SHOULD DROP BELOW GALES BY MID AFTERNOON. WINDS BACK TO THE SOUTHWEST ON TUESDAY AS LOW PRESSURE MOVES EAST ACROSS THE CANADIAN PRAIRIES. SOUTHERLY GALES MAY BE POSSIBLE AGAIN ON WEDNESDAY AHEAD OF AN APPROACHING COLD FRONT. BMD && .LOT WATCHES/WARNINGS/ADVISORIES... IL...WIND ADVISORY...ILZ010-ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020- ILZ021-ILZ022-ILZ023-ILZ032-ILZ033-ILZ039...10 AM SUNDAY TO 8 PM SUNDAY. IN...WIND ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019...10 AM SUNDAY TO 8 PM SUNDAY. LM...GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565- LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868- LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 3 PM MONDAY. GALE WARNING...NEARSHORE WATERS UNTIL 4 AM MONDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
216 PM CST SAT NOV 16 2013 .DISCUSSION... 1230 PM CST ONLY SMALL CHANGES MADE TO THIS AFTERNOON FORECAST. SHOWER COVERAGE WILL FURTHER INCREASE AHEAD OF THE WELL-DEFINED SHORT WAVE TROUGH LIFTING NORTHEAST FROM THE NE/IA BORDER. THE MOISTURE TRANSPORT NOSE ALONG WITH ELEVATED STEEP LAPSE RATES SEEN ON 12Z REGIONAL SOUNDINGS WILL CONTINUE TO ADVECT OVER THE AREA SUPPORTING AND REPLENISHING THIS ACTIVITY INTO EARLY EVE. SEVERE POTENTIAL REMAINS VERY LOW WITH THIS. TEMPERATURES SHOULD CONTINUE TO WARM ESPECIALLY OUTSIDE OF THE SHOWERS...JUST SIMPLY BY PURE ADVECTION. PRONOUNCED REGIONAL SEVERE THREAT CONTINUES FOR LATE TONIGHT INTO SUNDAY AFTERNOON. NEW SPC MODERATE RISK DOES INCLUDE A LARGER PORTION OF THE FORECAST AREA...INCLUDING ALL OF CHICAGOLAND. UPDATED DISCUSSION ON THIS WILL BE POSTED BY 300 PM. MTF //PREV DISCUSSION... 815 AM CST FORECAST UPDATED TO ADD DRIZZLE IN THROUGH THIS MORNING. THE LOW-LEVEL MOISTURE SURGE CONTINUES TO RETURN OVER THE AREA. ISENTROPIC ASCENT ON THE RAP ANALYSIS OF 285K AND 290K SURFACES HAS RAPIDLY SATURATED AND LOOKS TO BE THE ROOT OF THIS. EVEN ON THE 12Z ILX RAOB...THE PROFILE WAS VERY SUGGESTIVE OF DRIZZLE. THIS COULD CONTINUE INTO THIS AFTERNOON BASED ON THE EXTENT OF UPSTREAM OBS ACROSS CENTRAL AND SOUTHERN IL. SOUTH WINDS CONTINUE TO BRING WARM AIR ADVECTION SO TEMPERATURES WILL INCH UPWARD. THE CHANCE FOR TRUE SHOWERS AND POSSIBLY SOME STORMS TODAY STILL LOOKS TO ARRIVE WITH A SHORT WAVE ACROSS THE WESTERN FORECAST AREA BY EARLY AFTERNOON AND SPREADING EAST FROM THERE. MTF //PREV DISCUSSION... 333 AM...FORECAST FOCUS REMAINS POTENTIAL SEVERE WEATHER OUTBREAK ACROSS THE SOUTHERN LAKES AND OHIO VALLEY ON SUNDAY. IN THE SHORT TERM...LOW CLOUDS HAVE STREAMED NORTH ACROSS THE AREA SIGNALING THE BEGINNING OF A SURGE OF LOW LEVEL MOISTURE. DEWPOINTS SLOWLY CREEPING INTO THE LOWER 40S EARLY THIS MORNING WILL CONTINUE TO RISE INTO THE LOWER/MID 50S THIS AFTERNOON...UPPER 50S TONIGHT AND LIKELY POOL IN THE LOWER TO PERHAPS MID 60S JUST AHEAD OF THE COLD FRONT SUNDAY MORNING. LOW PRESSURE OVER NEBRASKA WILL LIFT NORTH TO MINNESOTA BY THIS EVENING AND AS IT DOES...AN UPPER LEVEL WAVE WILL MOVE ACROSS THE AREA THIS AFTERNOON INTO THIS EVENING. MUCH OF THE EASTERN HALF OR TWO THIRDS WILL LIKELY REMAIN DRY THIS MORNING WITH PRECIP SPREADING ACROSS THE WESTERN CWA BY LATE MORNING. HAVE INCLUDED JUST A CHANCE OF THUNDERSTORMS WITH THE STRONGER/CONVECTIVE ELEMENTS BUT CONFIDENCE REGARDING HOW WIDESPREAD LIGHTNING/THUNDER WILL BECOME IS SOMEWHAT LOW AND THUNDER COVERAGE MAY NEED TO BE INCREASED BASED ON SHORT TERM TRENDS ONCE PRECIP DEVELOPS/ARRIVES. THIS ACTIVITY SHOULD MOVE NORTHEAST OF THE AREA BY MID/LATE EVENING WITH A POSSIBLE LULL IN ACTIVITY INTO THE EARLY MORNING HOURS. NOT EXPECTING ANY OF THE THUNDERSTORMS DURING THIS FIRST WAVE TO BE SEVERE. SOME COULD PRODUCE STRONG/GUSTY WINDS AS WELL AS HEAVY RAIN. THOUGH STORM MOTION SHOULD BE SUFFICIENTLY FAST TO PREVENT A LONG DURATION HEAVY RAIN IN ANY ONE LOCATION. RAINFALL AMOUNTS WITH THIS WAVE APPEAR TO BE IN THE 0.5 TO 0.75 RANGE. DESPITE MAINLY CLOUDY SKIES TODAY AND THEN PRECIP THIS AFTERNOON...WITH THE NOTED SURGE IN LOW LEVEL MOISTURE...TEMPS WILL CONTINUE TO CLIMB THROUGH THE DAY WITH CURRENT TEMPS ALREADY IN THE LOWER 50S ACROSS SOUTHERN IL. THUS...HIGHS IN THE UPPER 50S TO LOWER 60S LOOK ON TRACK AND MUCH OF THE SOUTHERN THIRD/HALF OF THE CWA MAY NOT SEE PRECIP UNTIL LATE THIS AFTERNOON AND IF ANY BREAKS DEVELOP...THIS WILL AID TEMPS FURTHER. AS PRECIP ENDS THIS EVENING...POSSIBLE FOR SOME LOCATIONS...ESPECIALLY NORTHERN CWA...TO CONTINUE TO WARM WITH HIGHS BEING REACHED IN THE EVENING. A SECOND LOW THEN DEVELOPS OVER EASTERN COLORADO TONIGHT AND QUICKLY SHIFTS EAST TO IOWA BY SUNDAY MORNING...THEN RAPIDLY DEEPENS AS IT ABSORBS THE FIRST LOW OVER MINNESOTA...AND REACHES LAKE SUPERIOR BY SUNDAY EVENING. A STRONG COLD FRONT WILL RACE ACROSS THE CWA FROM MID/LATE SUNDAY MORNING THROUGH EARLY/MID SUNDAY AFTERNOON. ANOTHER WAVE OF THUNDERSTORMS IS POSSIBLE IN THE EARLY MORNING HOURS OF SUNDAY AHEAD OF THIS SECOND LOW... DEVELOPING OVER EASTERN IOWA AND NORTHWEST IL THEN MOVING INTO SOUTHERN WI...MOSTLY LIKELY BY SUNRISE. AT THE SAME TIME... ADDITIONAL THUNDERSTORMS COULD BE DEVELOPING AHEAD OF THE COLD FRONT ACROSS PARTS OF IOWA/MISSOURI. ANY OF THESE THUNDERSTORMS OVERNIGHT INTO EARLY SUNDAY MORNING COULD BECOME SEVERE. BUT TO WHAT EXTENT AND HOW WIDESPREAD ANY SEVERE WEATHER WOULD BECOME IS UNCERTAIN. HOWEVER...WITH SUCH WARM/MOIST LOW LEVELS...A DEEPENING SURFACE LOW AND WHAT COULD END UP BEING A WARM FRONTAL BOUNDARY ACROSS THE NORTHERN CWA...THE THREAT OF A TORNADO WITH ANY STRONG STORMS CAN/T BE RULED OUT. ANOTHER BRIEF LULL IS EXPECTED SUNDAY MORNING BEFORE WHAT APPEARS LIKE IT COULD BE THE BEGINNING OF A WIDESPREAD SEVERE WEATHER OUTBREAK DEVELOPS. WINDS THROUGH THE ENTIRE COLUMN REMAIN VERY IMPRESSIVE WITH 50 KNOTS AS LOW AS 900MB SUNDAY MORNING. AS NOTED...WHILE THE WARM/MOIST CONDITIONS WILL HELP/AID STORMS STAYING SURFACE BASED...EXPECT QUITE A BIT OF CLOUD COVER...AND WHILE HAVE TRIED TO SHOW SOME PARTLY/MOSTLY CLOUDY CONDITIONS AT LEAST ACROSS THE SOUTHEAST CWA SUNDAY MORNING...ITS POSSIBLE OVERCAST CONDITIONS WILL PERSIST UNTIL FROPA. ADDITIONAL UNCERTAINTY REMAINS WITH WHERE/WHEN THUNDERSTORMS WILL DEVELOP... JUST WEST OF THE CWA...OVER THE CWA...EASTERN CWA/NORTHWEST INDIANA. ENTIRE CWA IS NOW INCLUDED IN SLIGHT RISK PER THIS MORNING/S SPC DAY2 OUTLOOK WITH MODERATE RISK EAST OF THE I-55/I-57 CORRIDOR. POTENTIAL IS CERTAINLY HIGHER OVER THE EASTERN CWA BUT EVEN FROM THIS DISTANCE WILL BE INCLUDING SEVERE MENTION/DAMAGING WINDS IN THE ZONES/GRIDS. THUNDERSTORMS WILL BE ENDING FROM WEST TO EAST DURING THE MID/LATE AFTERNOON AND ALSO ATTEMPTED TO INCLUDE THIS TIMING IN THE GRIDS. THE THREAT OF A TORNADO OR TWO WILL REMAIN SUNDAY BUT DAMAGING WINDS APPEAR TO BE THE PRIMARY SEVERE WEATHER THREAT. DESPITE PRECIPITABLE WATER VALUES ONLY AROUND AN INCH...EXPECT VERY EFFICIENT RAIN PRODUCTION WITH ANOTHER 0.5-0.75 INCHES POSSIBLE...ALTHOUGH PERHAPS MORE LOCALIZED DEPENDING ON CONVECTIVE COVERAGE. STRONG WINDS FROM THE SOUTH WILL DEVELOP TODAY WITH GUSTS INTO THE 30-35 MPH RANGE POSSIBLE. STILL APPEARS THERE COULD BE A 3-6 HOUR WINDOW THIS EVENING OF GUSTS 40+ MPH BEFORE WINDS DIMINISH SOME OVERNIGHT...WHILE CLOSE TO WIND ADVISORY CRITERIA...NOT SURE IT WILL BE REACHED AND NO HEADLINES THROUGH TONIGHT. BY SUNDAY... LOW LEVEL WINDS ARE WELL INTO ADVISORY CRITERIA AND SOME OF THIS WILL LIKELY MIX TO THE SURFACE ESPECIALLY JUST BEHIND THE STORMS/ COLD FRONT AS COLD ADVECTION IS AIDED BY LARGE PRESSURE RISES. THIS IS THIRD PERIOD AND A BIT EARLY FOR AN ADVISORY AND LATER SHIFTS WILL NEED TO ASSESS WIND POTENTIAL/HEADLINES FOR SUNDAY. HAVE CONTINUED INCREASING HIGH TEMPS FOR SUNDAY WITH MID 60S NORTH TO UPPER 60S FROM I-55 SOUTH AND ITS QUITE POSSIBLE SOME AREAS MAY SEE TEMPS TAG 70 AHEAD OF THE FRONT...ESPECIALLY WITH ANY BREAKS IN THE OVERCAST AS 850MB TEMPS ARE NOW EXPECTED TO BE IN THE +12C TO +15C RANGE. WRAP AROUND SHOWERS WILL BE POSSIBLE SUNDAY EVENING BUT SHOULD BE ENDING FAIRLY QUICKLY WITH CLEARING SKIES OVERNIGHT AS HIGH PRESSURE BUILDS INTO THE REGION MONDAY AFTERNOON/MONDAY NIGHT AND THIS HIGH IS MOVING FASTER THAN PREVIOUS MODELS HAD SUGGESTED. WHILE IT WILL TURN MUCH COLDER MONDAY NIGHT WITH LOWS IN THE 30S... MONDAY MAY END UP BEING MAINLY SUNNY WITH DIMINISHING WINDS IN THE AFTERNOON AND TEMPS REBOUNDING BACK INTO THE MID 40S. STILL WILL FEEL MUCH COLDER COMPARED TO SUNDAY...BUT THE TREND IS SLIGHTLY WARMER. HAVE CONTINUED THE WARMING TREND TUESDAY THROUGH THURSDAY AS WINDS TURN SOUTHERLY SOONER ON THE BACK SIDE OF THE DEPARTING HIGH. ALSO NOW APPEARS THE CHANCE OF SHOWERS WILL ARRIVE SOONER...PERHAPS AS EARLY AS LATE WEDNESDAY BUT CERTAINLY WEDNESDAY NIGHT INTO THURSDAY. WARMING TEMPS DURING THIS PERIOD WITH SOUTHERLY FLOW SHOULD KEEP PRECIP MAINLY LIQUID. A COLD FRONT THEN MOVES SOUTH THURSDAY NIGHT AND FRIDAY WITH THE ECMWF MUCH COLDER THAN THE GFS AND HAVE LOWERED TEMPS A FEW DEGREES DURING THIS TIME PERIOD AND WHILE ITS STILL SEVERAL DAYS AWAY...POTENTIAL FOR SOME FROZEN PRECIP EXISTS LATER FRIDAY/FRIDAY NIGHT...DEPENDING ON SPEED OF FRONT AND END TIME OF PRECIP. CMS && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 18Z... * IFR CIGS THIS AFTERNOON AND POTENTIALLY THROUGH TONIGHT. * SHRA WITH GRADUALLY INCREASING CHANCES FOR THUNDER THROUGH EARLY EVE. * SOUTH WINDS GUSTING TO AROUND 30 KT AT TIMES THROUGH THIS EVE...THEN TURNING SOUTHWEST AND BECOMING EVEN MORE GUSTY ON SUNDAY AFTERNOON. * LOW LEVEL WIND SHEAR POSSIBLE AS WINDS NEAR 1500 FT INCREASE TO 50 KT OR STRONGER. * TSRA CHANCES INCREASING AROUND DAYBREAK WITH GUSTY SEVERE STORM POTENTIAL THIS MORNING AND EARLY AFTERNOON. //DISCUSSION...UPDATED 18Z... INITIAL LOW PRESSURE MOVING NORTHWARD INTO MN CONTINUES TO INCREASE SOUTHERLY WINDS ACROSS THE AREA...AND AS AN EVEN MORE POTENT LOW PRESSURE DEVELOPS ON SUNDAY THE SOUTH WINDS WILL REALLY RAMP UP. SOUTHERLY GUSTS TO 30 KT OR EVEN SLIGHTLY HIGHER MAY BE SEEN THIS AFTERNOON. SHOWERS WITH EMBEDDED SCATTERED THUNDER WILL INCREASE IN COVERAGE THROUGH LATE AFTERNOON WITH THIS INITIAL LOW PRESSURE. THERE PROBABLY WILL BE A SLIGHT DIMINISHING IN COVERAGE THEN THROUGH THE MID TO LATE EVE AS THIS INITIAL MOISTURE SURGE PASSES. BUT AS INFLUENCE OF THE SECOND WEATHER SYSTEM BEGINS TO OVERSPREAD THE AREA...SCATTERED STORMS ARE LIKELY TO DEVELOP OVERNIGHT INTO SUNDAY MORNING THAT WILL ADVANCING NORTHWARD. THUNDER POTENTIAL WILL MAXIMIZE DURING THE LATE MORNING THROUGH MID AFTERNOON FOR THE CHICAGO AREA TAF SITES. SOME OF THESE COULD BE SEVERE GIVEN THE POTENT WIND FIELD AND SURPRISING INSTABILITY WITHIN THIS SYSTEM FOR THIS TIME OF YEAR. WINDS AROUND AND UNDER THESE STORMS WILL BE ESPECIALLY GUSTY...BUT EVEN THE PREVAILING WINDS WILL BE VERY GUSTY BY AFTERNOON...WITH GUSTS OF 35KT+. MTF //ORD AND MDW CONFIDENCE...UPDATED 18Z... * MEDIUM TO HIGH CONFIDENCE IN IFR CIGS THROUGH EARLY EVE. * HIGH CONFIDENCE IN SHRA THROUGH EARLY THIS EVE. * HIGH CONFIDENCE IN WIND DIRECTION...SPEEDS...AND GUSTS THROUGH 18Z SUNDAY...MEDIUM CONFIDENCE AFTER. * HIGH CONFIDENCE IN 50-60KT SW WINDS IN THE 1500-3000FT LAYER THIS EVE. * MEDIUM CONFIDENCE IN TSRA TIMING THROUGHOUT THE TAF. HIGH CONFIDENCE THAT IF STRONG TO SEVERE STORMS OCCUR AT THE AIRPORTS THEY WOULD BE BE AFTER 10Z...AND MOST PROBABLE 17Z-21Z. //OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z... SUNDAY NIGHT...BREEZY WEST WINDS DIMINISHING LATE. MONDAY THROUGH WEDNESDAY...VFR. THURSDAY AND FRIDAY...SLIGHT CHANCE SHRA DURING THE DAY AND RASN AT NIGHT. MAINLY VFR. MDB && .MARINE... 215 PM CST A STRONG STORM SYSTEM WILL IMPACT THE GREAT LAKES REGION OVER THE WEEKEND BRINGING PERIODS OF GALES WITH STORM FORCE WINDS A POSSIBILITY ON THE BACK END OF THE SYSTEM. BROAD AREA OF LOW PRESSURE IS BEGINNING TO CONSOLIDATE OVER THE NORTHERN PLAINS TODAY...BUT WILL SIGNIFICANTLY DEEPEN OVER WISCONSIN EARLY SUNDAY AFTERNOON...THEN CONTINUE TO DEEPEN AS IT MOVES ACROSS NORTHERN LAKE MICHIGAN SUNDAY EVENING. SOUTHERLY GALES WILL CONTINUE THROUGH THE OVERNIGHT HOURS INTO EARLY SUNDAY. THESE WINDS WILL TRANSPORT MOIST AIR NORTH OVER THE WATERS WHICH IS EXPECTED TO LEAD TO AREAS OF FOG DEVELOPMENT. IT IS UNCERTAIN HOW WIDESPREAD OR DENSE THE FOG WILL BE...BUT A FOG ADVISORY IS NOT OUT OF THE REALM OF POSSIBILITY. WINDS ARE EXPECTED TO EASE SLIGHTLY BELOW GALES DURING PORTIONS OF THE DAY SUNDAY...ESPECIALLY THE NORTHERN HALF OF THE LAKE WHERE THE GRADIENT WILL WEAKEN NEAR THE LOW CENTER. AFTER THE LOW AND ATTENDANT COLD FRONT PUSH EAST OF THE LAKE SUNDAY EVENING...WINDS WILL TURN WESTERLY AND QUICKLY RAMP BACK UP TO STRONG GALES OF 40 TO 45 KT...WITH OCCASIONAL STORM FORCE GUSTS STILL A POSSIBILITY. WINDS WILL SLOWLY TAPER MONDAY AS A RIDGE OF HIGH PRESSURE BUILDS ACROSS THE MISSISSIPPI VALLEY...AND SHOULD DROP BELOW GALES BY MID AFTERNOON. WINDS BACK TO THE SOUTHWEST ON TUESDAY AS LOW PRESSURE MOVES EAST ACROSS THE CANADIAN PRAIRIES. SOUTHERLY GALES MAY BE POSSIBLE AGAIN ON WEDNESDAY AHEAD OF AN APPROACHING COLD FRONT. BMD && .LOT WATCHES/WARNINGS/ADVISORIES... IL...WIND ADVISORY...ILZ010-ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020- ILZ021-ILZ022-ILZ023-ILZ032-ILZ033-ILZ039...10 AM SUNDAY TO 8 PM SUNDAY. IN...WIND ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019...10 AM SUNDAY TO 8 PM SUNDAY. LM...GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565- LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868- LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 3 PM MONDAY. GALE WARNING...NEARSHORE WATERS UNTIL 4 AM MONDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION...UPDATED
NWS CHICAGO/ROMEOVILLE IL
1233 PM CST SAT NOV 16 2013 .DISCUSSION... 1230 PM CST ONLY SMALL CHANGES MADE TO THIS AFTERNOON FORECAST. SHOWER COVERAGE WILL FURTHER INCREASE AHEAD OF THE WELL-DEFINED SHORT WAVE TROUGH LIFTING NORTHEAST FROM THE NE/IA BORDER. THE MOISTURE TRANSPORT NOSE ALONG WITH ELEVATED STEEP LAPSE RATES SEEN ON 12Z REGIONAL SOUNDINGS WILL CONTINUE TO ADVECT OVER THE AREA SUPPORTING AND REPLENISHING THIS ACTIVITY INTO EARLY EVE. SEVERE POTENTIAL REMAINS VERY LOW WITH THIS. TEMPERATURES SHOULD CONTINUE TO WARM ESPECIALLY OUTSIDE OF THE SHOWERS...JUST SIMPLY BY PURE ADVECTION. PRONOUNCED REGIONAL SEVERE THREAT CONTINUES FOR LATE TONIGHT INTO SUNDAY AFTERNOON. NEW SPC MODERATE RISK DOES INCLUDE A LARGER PORTION OF THE FORECAST AREA...INCLUDING ALL OF CHICAGOLAND. UPDATED DISCUSSION ON THIS WILL BE POSTED BY 300 PM. MTF && .PREV DISCUSSION... 815 AM CST FORECAST UPDATED TO ADD DRIZZLE IN THROUGH THIS MORNING. THE LOW-LEVEL MOISTURE SURGE CONTINUES TO RETURN OVER THE AREA. ISENTROPIC ASCENT ON THE RAP ANALYSIS OF 285K AND 290K SURFACES HAS RAPIDLY SATURATED AND LOOKS TO BE THE ROOT OF THIS. EVEN ON THE 12Z ILX RAOB...THE PROFILE WAS VERY SUGGESTIVE OF DRIZZLE. THIS COULD CONTINUE INTO THIS AFTERNOON BASED ON THE EXTENT OF UPSTREAM OBS ACROSS CENTRAL AND SOUTHERN IL. SOUTH WINDS CONTINUE TO BRING WARM AIR ADVECTION SO TEMPERATURES WILL INCH UPWARD. THE CHANCE FOR TRUE SHOWERS AND POSSIBLY SOME STORMS TODAY STILL LOOKS TO ARRIVE WITH A SHORT WAVE ACROSS THE WESTERN FORECAST AREA BY EARLY AFTERNOON AND SPREADING EAST FROM THERE. MTF //PREV DISCUSSION... 333 AM...FORECAST FOCUS REMAINS POTENTIAL SEVERE WEATHER OUTBREAK ACROSS THE SOUTHERN LAKES AND OHIO VALLEY ON SUNDAY. IN THE SHORT TERM...LOW CLOUDS HAVE STREAMED NORTH ACROSS THE AREA SIGNALING THE BEGINNING OF A SURGE OF LOW LEVEL MOISTURE. DEWPOINTS SLOWLY CREEPING INTO THE LOWER 40S EARLY THIS MORNING WILL CONTINUE TO RISE INTO THE LOWER/MID 50S THIS AFTERNOON...UPPER 50S TONIGHT AND LIKELY POOL IN THE LOWER TO PERHAPS MID 60S JUST AHEAD OF THE COLD FRONT SUNDAY MORNING. LOW PRESSURE OVER NEBRASKA WILL LIFT NORTH TO MINNESOTA BY THIS EVENING AND AS IT DOES...AN UPPER LEVEL WAVE WILL MOVE ACROSS THE AREA THIS AFTERNOON INTO THIS EVENING. MUCH OF THE EASTERN HALF OR TWO THIRDS WILL LIKELY REMAIN DRY THIS MORNING WITH PRECIP SPREADING ACROSS THE WESTERN CWA BY LATE MORNING. HAVE INCLUDED JUST A CHANCE OF THUNDERSTORMS WITH THE STRONGER/CONVECTIVE ELEMENTS BUT CONFIDENCE REGARDING HOW WIDESPREAD LIGHTNING/THUNDER WILL BECOME IS SOMEWHAT LOW AND THUNDER COVERAGE MAY NEED TO BE INCREASED BASED ON SHORT TERM TRENDS ONCE PRECIP DEVELOPS/ARRIVES. THIS ACTIVITY SHOULD MOVE NORTHEAST OF THE AREA BY MID/LATE EVENING WITH A POSSIBLE LULL IN ACTIVITY INTO THE EARLY MORNING HOURS. NOT EXPECTING ANY OF THE THUNDERSTORMS DURING THIS FIRST WAVE TO BE SEVERE. SOME COULD PRODUCE STRONG/GUSTY WINDS AS WELL AS HEAVY RAIN. THOUGH STORM MOTION SHOULD BE SUFFICIENTLY FAST TO PREVENT A LONG DURATION HEAVY RAIN IN ANY ONE LOCATION. RAINFALL AMOUNTS WITH THIS WAVE APPEAR TO BE IN THE 0.5 TO 0.75 RANGE. DESPITE MAINLY CLOUDY SKIES TODAY AND THEN PRECIP THIS AFTERNOON...WITH THE NOTED SURGE IN LOW LEVEL MOISTURE...TEMPS WILL CONTINUE TO CLIMB THROUGH THE DAY WITH CURRENT TEMPS ALREADY IN THE LOWER 50S ACROSS SOUTHERN IL. THUS...HIGHS IN THE UPPER 50S TO LOWER 60S LOOK ON TRACK AND MUCH OF THE SOUTHERN THIRD/HALF OF THE CWA MAY NOT SEE PRECIP UNTIL LATE THIS AFTERNOON AND IF ANY BREAKS DEVELOP...THIS WILL AID TEMPS FURTHER. AS PRECIP ENDS THIS EVENING...POSSIBLE FOR SOME LOCATIONS...ESPECIALLY NORTHERN CWA...TO CONTINUE TO WARM WITH HIGHS BEING REACHED IN THE EVENING. A SECOND LOW THEN DEVELOPS OVER EASTERN COLORADO TONIGHT AND QUICKLY SHIFTS EAST TO IOWA BY SUNDAY MORNING...THEN RAPIDLY DEEPENS AS IT ABSORBS THE FIRST LOW OVER MINNESOTA...AND REACHES LAKE SUPERIOR BY SUNDAY EVENING. A STRONG COLD FRONT WILL RACE ACROSS THE CWA FROM MID/LATE SUNDAY MORNING THROUGH EARLY/MID SUNDAY AFTERNOON. ANOTHER WAVE OF THUNDERSTORMS IS POSSIBLE IN THE EARLY MORNING HOURS OF SUNDAY AHEAD OF THIS SECOND LOW... DEVELOPING OVER EASTERN IOWA AND NORTHWEST IL THEN MOVING INTO SOUTHERN WI...MOSTLY LIKELY BY SUNRISE. AT THE SAME TIME... ADDITIONAL THUNDERSTORMS COULD BE DEVELOPING AHEAD OF THE COLD FRONT ACROSS PARTS OF IOWA/MISSOURI. ANY OF THESE THUNDERSTORMS OVERNIGHT INTO EARLY SUNDAY MORNING COULD BECOME SEVERE. BUT TO WHAT EXTENT AND HOW WIDESPREAD ANY SEVERE WEATHER WOULD BECOME IS UNCERTAIN. HOWEVER...WITH SUCH WARM/MOIST LOW LEVELS...A DEEPENING SURFACE LOW AND WHAT COULD END UP BEING A WARM FRONTAL BOUNDARY ACROSS THE NORTHERN CWA...THE THREAT OF A TORNADO WITH ANY STRONG STORMS CAN/T BE RULED OUT. ANOTHER BRIEF LULL IS EXPECTED SUNDAY MORNING BEFORE WHAT APPEARS LIKE IT COULD BE THE BEGINNING OF A WIDESPREAD SEVERE WEATHER OUTBREAK DEVELOPS. WINDS THROUGH THE ENTIRE COLUMN REMAIN VERY IMPRESSIVE WITH 50 KNOTS AS LOW AS 900MB SUNDAY MORNING. AS NOTED...WHILE THE WARM/MOIST CONDITIONS WILL HELP/AID STORMS STAYING SURFACE BASED...EXPECT QUITE A BIT OF CLOUD COVER...AND WHILE HAVE TRIED TO SHOW SOME PARTLY/MOSTLY CLOUDY CONDITIONS AT LEAST ACROSS THE SOUTHEAST CWA SUNDAY MORNING...ITS POSSIBLE OVERCAST CONDITIONS WILL PERSIST UNTIL FROPA. ADDITIONAL UNCERTAINTY REMAINS WITH WHERE/WHEN THUNDERSTORMS WILL DEVELOP... JUST WEST OF THE CWA...OVER THE CWA...EASTERN CWA/NORTHWEST INDIANA. ENTIRE CWA IS NOW INCLUDED IN SLIGHT RISK PER THIS MORNING/S SPC DAY2 OUTLOOK WITH MODERATE RISK EAST OF THE I-55/I-57 CORRIDOR. POTENTIAL IS CERTAINLY HIGHER OVER THE EASTERN CWA BUT EVEN FROM THIS DISTANCE WILL BE INCLUDING SEVERE MENTION/DAMAGING WINDS IN THE ZONES/GRIDS. THUNDERSTORMS WILL BE ENDING FROM WEST TO EAST DURING THE MID/LATE AFTERNOON AND ALSO ATTEMPTED TO INCLUDE THIS TIMING IN THE GRIDS. THE THREAT OF A TORNADO OR TWO WILL REMAIN SUNDAY BUT DAMAGING WINDS APPEAR TO BE THE PRIMARY SEVERE WEATHER THREAT. DESPITE PRECIPITABLE WATER VALUES ONLY AROUND AN INCH...EXPECT VERY EFFICIENT RAIN PRODUCTION WITH ANOTHER 0.5-0.75 INCHES POSSIBLE...ALTHOUGH PERHAPS MORE LOCALIZED DEPENDING ON CONVECTIVE COVERAGE. STRONG WINDS FROM THE SOUTH WILL DEVELOP TODAY WITH GUSTS INTO THE 30-35 MPH RANGE POSSIBLE. STILL APPEARS THERE COULD BE A 3-6 HOUR WINDOW THIS EVENING OF GUSTS 40+ MPH BEFORE WINDS DIMINISH SOME OVERNIGHT...WHILE CLOSE TO WIND ADVISORY CRITERIA...NOT SURE IT WILL BE REACHED AND NO HEADLINES THROUGH TONIGHT. BY SUNDAY... LOW LEVEL WINDS ARE WELL INTO ADVISORY CRITERIA AND SOME OF THIS WILL LIKELY MIX TO THE SURFACE ESPECIALLY JUST BEHIND THE STORMS/ COLD FRONT AS COLD ADVECTION IS AIDED BY LARGE PRESSURE RISES. THIS IS THIRD PERIOD AND A BIT EARLY FOR AN ADVISORY AND LATER SHIFTS WILL NEED TO ASSESS WIND POTENTIAL/HEADLINES FOR SUNDAY. HAVE CONTINUED INCREASING HIGH TEMPS FOR SUNDAY WITH MID 60S NORTH TO UPPER 60S FROM I-55 SOUTH AND ITS QUITE POSSIBLE SOME AREAS MAY SEE TEMPS TAG 70 AHEAD OF THE FRONT...ESPECIALLY WITH ANY BREAKS IN THE OVERCAST AS 850MB TEMPS ARE NOW EXPECTED TO BE IN THE +12C TO +15C RANGE. WRAP AROUND SHOWERS WILL BE POSSIBLE SUNDAY EVENING BUT SHOULD BE ENDING FAIRLY QUICKLY WITH CLEARING SKIES OVERNIGHT AS HIGH PRESSURE BUILDS INTO THE REGION MONDAY AFTERNOON/MONDAY NIGHT AND THIS HIGH IS MOVING FASTER THAN PREVIOUS MODELS HAD SUGGESTED. WHILE IT WILL TURN MUCH COLDER MONDAY NIGHT WITH LOWS IN THE 30S... MONDAY MAY END UP BEING MAINLY SUNNY WITH DIMINISHING WINDS IN THE AFTERNOON AND TEMPS REBOUNDING BACK INTO THE MID 40S. STILL WILL FEEL MUCH COLDER COMPARED TO SUNDAY...BUT THE TREND IS SLIGHTLY WARMER. HAVE CONTINUED THE WARMING TREND TUESDAY THROUGH THURSDAY AS WINDS TURN SOUTHERLY SOONER ON THE BACK SIDE OF THE DEPARTING HIGH. ALSO NOW APPEARS THE CHANCE OF SHOWERS WILL ARRIVE SOONER...PERHAPS AS EARLY AS LATE WEDNESDAY BUT CERTAINLY WEDNESDAY NIGHT INTO THURSDAY. WARMING TEMPS DURING THIS PERIOD WITH SOUTHERLY FLOW SHOULD KEEP PRECIP MAINLY LIQUID. A COLD FRONT THEN MOVES SOUTH THURSDAY NIGHT AND FRIDAY WITH THE ECMWF MUCH COLDER THAN THE GFS AND HAVE LOWERED TEMPS A FEW DEGREES DURING THIS TIME PERIOD AND WHILE ITS STILL SEVERAL DAYS AWAY...POTENTIAL FOR SOME FROZEN PRECIP EXISTS LATER FRIDAY/FRIDAY NIGHT...DEPENDING ON SPEED OF FRONT AND END TIME OF PRECIP. CMS && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 18Z... * IFR CIGS THIS AFTERNOON AND POTENTIALLY THROUGH TONIGHT. * SHRA WITH GRADUALLY INCREASING CHANCES FOR THUNDER THROUGH EARLY EVE. * SOUTH WINDS GUSTING TO AROUND 30 KT AT TIMES THROUGH THIS EVE...THEN TURNING SOUTHWEST AND BECOMING EVEN MORE GUSTY ON SUNDAY AFTERNOON. * LOW LEVEL WIND SHEAR POSSIBLE AS WINDS NEAR 1500 FT INCREASE TO 50 KT OR STRONGER. * TSRA CHANCES INCREASING AROUND DAYBREAK WITH GUSTY SEVERE STORM POTENTIAL THIS MORNING AND EARLY AFTERNOON. //DISCUSSION...UPDATED 18Z... INITIAL LOW PRESSURE MOVING NORTHWARD INTO MN CONTINUES TO INCREASE SOUTHERLY WINDS ACROSS THE AREA...AND AS AN EVEN MORE POTENT LOW PRESSURE DEVELOPS ON SUNDAY THE SOUTH WINDS WILL REALLY RAMP UP. SOUTHERLY GUSTS TO 30 KT OR EVEN SLIGHTLY HIGHER MAY BE SEEN THIS AFTERNOON. SHOWERS WITH EMBEDDED SCATTERED THUNDER WILL INCREASE IN COVERAGE THROUGH LATE AFTERNOON WITH THIS INITIAL LOW PRESSURE. THERE PROBABLY WILL BE A SLIGHT DIMINISHING IN COVERAGE THEN THROUGH THE MID TO LATE EVE AS THIS INITIAL MOISTURE SURGE PASSES. BUT AS INFLUENCE OF THE SECOND WEATHER SYSTEM BEGINS TO OVERSPREAD THE AREA...SCATTERED STORMS ARE LIKELY TO DEVELOP OVERNIGHT INTO SUNDAY MORNING THAT WILL ADVANCING NORTHWARD. THUNDER POTENTIAL WILL MAXIMIZE DURING THE LATE MORNING THROUGH MID AFTERNOON FOR THE CHICAGO AREA TAF SITES. SOME OF THESE COULD BE SEVERE GIVEN THE POTENT WIND FIELD AND SURPRISING INSTABILITY WITHIN THIS SYSTEM FOR THIS TIME OF YEAR. WINDS AROUND AND UNDER THESE STORMS WILL BE ESPECIALLY GUSTY...BUT EVEN THE PREVAILING WINDS WILL BE VERY GUSTY BY AFTERNOON...WITH GUSTS OF 35KT+. MTF //ORD AND MDW CONFIDENCE...UPDATED 18Z... * MEDIUM TO HIGH CONFIDENCE IN IFR CIGS THROUGH EARLY EVE. * HIGH CONFIDENCE IN SHRA THROUGH EARLY THIS EVE. * HIGH CONFIDENCE IN WIND DIRECTION...SPEEDS...AND GUSTS THROUGH 18Z SUNDAY...MEDIUM CONFIDENCE AFTER. * HIGH CONFIDENCE IN 50-60KT SW WINDS IN THE 1500-3000FT LAYER THIS EVE. * MEDIUM CONFIDENCE IN TSRA TIMING THROUGHOUT THE TAF. HIGH CONFIDENCE THAT IF STRONG TO SEVERE STORMS OCCUR AT THE AIRPORTS THEY WOULD BE BE AFTER 10Z...AND MOST PROBABLE 17Z-21Z. //OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z... SUNDAY NIGHT...BREEZY WEST WINDS DIMINISHING LATE. MONDAY THROUGH WEDNESDAY...VFR. THURSDAY AND FRIDAY...SLIGHT CHANCE SHRA DURING THE DAY AND RASN AT NIGHT. MAINLY VFR. MDB && .MARINE... 354 AM CST GALES THROUGH MONDAY AND A POTENTIAL PERIOD OF STORM FORCE WINDS SUNDAY EVENING ARE THE FOCUS OF THIS FORECAST PERIOD. HIGH PRESSURE REMAINS CENTERED OFF THE EAST COAST WITH EFFECTS OF THE HIGH SPREAD BACK INTO THE EASTERN LAKES. LOW PRESSURE IS SPREAD ACROSS THE PLAINS AND UPPER MIDWEST WITH CONSOLIDATION EXPECTED TO OCCUR RESULTING IN A LOW TRACKING NORTHEAST TO WESTERN LAKE SUPERIOR SUNDAY MORNING. THE PRESSURE GRADIENT WILL TIGHTEN AS THIS LOW ORGANIZES ALLOWING SOUTH WINDS TO STEADILY INCREASE ACROSS THE LAKE TODAY. WARMER AIR WILL BE MOVING INTO THE REGION WHICH WILL CREATE SOME DEGREE OF A STABLE LAYER OVER THE LAKE TODAY BUT GALES ARE STILL LIKELY TO DEVELOP THIS AFTERNOON AND CONTINUE THIS EVENING. GALES WILL BE A BIT MORE MARGINAL IN THE IL/IN NEARSHORE WATERS BUT OPTED TO HOIST A GALE WARNING FOR THESE AREAS WITH 30 KT LIKELY AND DECENT POTENTIAL FOR GALE FORCE GUSTS WITH QUITE A BIT OF WIND JUST ABOVE THE SURFACE...WITH BETTER MIXING POSSIBLE THANKS TO AN OFFSHORE COMPONENT AT TIMES. WINDS WILL EASE UP FOR A BRIEF PERIOD LATE TONIGHT AND EARLY SUNDAY MORNING SO SPEEDS MAY FALL BELOW GALE FOR SEVERAL HOURS...BUT WINDS WILL INCREASE AGAIN BY SUNDAY AFTERNOON AS A STRONGER LOW EJECTS NORTHEAST FROM EASTERN COLORADO. THIS LOW WILL RAPIDLY DEEPEN AS IT REACHES WISCONSIN AND THE EASTERN U.P. OF MICHIGAN BY SUNDAY EVENING. MUCH WARMER AIR WILL BE DRAWN NORTHWARD ACROSS THE LAKE BUT THE GRADIENT WILL BE TIGHT ENOUGH TO SUPPORT GALES...EVEN IF MIXING IS VERY SHALLOW OVER THE COLDER LAKE WATER. NEARSHORE AREAS MAY SEE THE STRONGEST WINDS DURING THE DAY SUNDAY AS THE FLOW TURNS SOUTHWESTERLY AND WELL MIXED AIR MOVES OFFSHORE. A FURTHER SHIFT TO WESTERLY WINDS WILL OCCUR AS THE LOW FURTHER DEEPENS AND CONTINUES NORTHEAST DRAGGING A SHARP COLD FRONT ACROSS THE LAKE BY SUNDAY EVENING. WITH THE DEEPENING LOW AND UNSTABLE CONDITIONS DEVELOPING WINDS SHOULD INCREASE TO 45 KT WITH A DECENT POTENTIAL FOR 50 KT STORM FORCE WINDS SUNDAY EVENING AND EARLY SUNDAY NIGHT. HAVE DECIDED TO EXTEND THE GALE WARNING FROM LATE TONIGHT THROUGH MONDAY AFTERNOON AND EXPAND INTO THE NEARSHORE WATERS...WITH AN EARLIER END TIME. WILL NEED TO KEEP AN EYE ON THE DURATION OF ANY LULL PERIOD EARLY SUNDAY WHICH MAY ALLOW FOR A SHORT WINDOW WITHOUT A GALE BUT AT THIS POINT THE WINDOW LOOKS RATHER SHORT...ON THE ORDER OF 6-9 HOURS. STILL DO HAVE SOME UNCERTAINTY ON THE TRACK OF THE LOW...WHETHER IT CROSSES THE NORTHERN PART OF THE LAKE OR REMAINS JUST TO THE WEST AND NORTH. RIGHT NOW PREFER THE WESTERN TRACK WHICH WOULD PROVIDE A CLEANER SOUTHWEST TO WEST SHIFT OF THE WINDS AS OPPOSED THE EASTERLY TRACK WHICH WOULD RESULT IN A BRIEF PERIOD OF NORTHERLY WINDS OVER THE NORTHERN SECTIONS OF THE LAKE. WILL NEED TO KEEP AN EYE ON THIS. OTHERWISE WINDS WILL SLOWLY DIMINISH MONDAY AS HIGH PRESSURE PASSES TO THE SOUTH AND EAST OF THE LAKE. LOW PRESSURE IS THEN EXPECTED TO CROSS THE CANADIAN PRAIRIES TO JAMES BAY DURING THE MIDDLE OF NEXT WEEK BRINGING ANOTHER INCREASE IN SOUTH WINDS WHICH WILL FLIP NORTHWEST WITH A COLD FRONTAL PASSAGE LATER THURSDAY. MDB && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS UNTIL NOON SATURDAY. GALE WARNING...NEARSHORE WATERS UNTIL 4 AM MONDAY. GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565- LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868- LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 3 PM MONDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
341 PM EST SAT NOV 16 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 521 AM EST SAT NOV 16 2013 SOUTHWESTERLY FLOW IS BEGINNING TO INCREASE OVER THE CWA AS THE UPPER TROUGH AMPLIFIES DUE TO A STRONG SHORTWAVE MOVING SOUTHEAST THROUGH THE PACIFIC NORTHWEST. THIS SHORTWAVE WILL BE THE MAJOR PLAYER TO OUR WEATHER FOR THE SECOND HALF OF THE WEEKEND. FOR THE SHORT TERM...THE SOUTHWESTERLY FLOW ALOFT WILL ALLOW A SHORTWAVE CURRENTLY LOCATED NEAR THE FOUR CORNERS REGION TO MOVE NORTHEAST ACROSS THE UPPER GREAT LAKES LATE THIS AFTERNOON AND EVENING. MOISTURE STREAMING NORTHEAST ON WV IMAGERY IS LEADING TO SOME HIGH CLOUDS OVER MUCH OF UPPER MICHIGAN. IN THE LOWER LEVELS...INITIAL RAP SOUNDINGS SHOWING PLENTY OF DRY AIR BELOW THE HIGH CLOUDS BUT THERE WAS ENOUGH RADIATIONAL COOLING EARLIER THIS EVENING TO PRODUCE SOME PATCHY FOG OVER CENTRAL/EASTERN UPPER MICHIGAN. THE DRIER LOW LEVELS WILL LIKELY BE SHORT LIVED AS 3-5KFT CEILINGS COVER MUCH OF CENTRAL/NORTHERN WISCONSIN AND WILL BE MOVING INTO THE AREA OVER THE NEXT COUPLE OF HOURS. IN ADDITION TO THOSE CLOUDS...MODELS ARE SHOWING THE DEVELOPING 1KFT CEILINGS IN NORTHERN ILLINOIS TO QUICKLY LIFT NORTH AND EXPAND THIS MORNING AND EARLY AFTERNOON...COVERING MUCH OF UPPER MICHIGAN. THE SHORTWAVE WILL BE NEARING THE REGION THIS AFTERNOON AND THERE ARE SEVERAL FEATURES SUPPORTING A BROAD AREA OF RAIN MOVING THROUGH THE AREA LATE THIS AFTERNOON AND EVENING. FIRST...EXPECT THERE TO BE A WEAK COUPLED JET STRUCTURE OVER THE AREA THIS EVENING. BROAD MID LEVEL WARM AIR ADVECTION AND MOISTURE TRANSPORT WILL ACCOMPANY THIS SHORTWAVE...WITH THE EASTERN CWA SEEING THE BEST OF BOTH FEATURES. AT THE SURFACE...THE BROAD LOW DEVELOPING OVER THE CENTRAL/NORTHERN PLAINS WILL SLIDE A TROUGH THROUGH MINNESOTA TODAY AND OVER WESTERN LAKE SUPERIOR TONIGHT. HAVE HIGH CONFIDENCE IN THE FORECAST FOR THIS AFTERNOON/EVENING BASED OFF GREAT MODEL CONSISTENCY. SINCE THE BEST FORCING IS OVER THE SOUTHEAST HALF...WILL HAVE THE HIGHEST POPS/QPF IN THAT AREA BUT THERE WILL BE A PERIOD OF DEFINITE POPS OVER THE ENTIRE AREA. AS FOR QPF...EXPECT VALUES TO RANGE FROM 0.2 OVER THE WEST TO 0.75IN OVER THE EAST...WITH SOME HIGHER AMOUNTS IF THERE ARE SOME EMBEDDED THUNDERSTORMS. AS FOR THUNDER...THERE IS A POCKET OF 50-125J/KG OF MUCAPE AND SHOWALTER VALUES SLIGHTLY BELOW 0 OVER THE EASTERN 2/3RDS OF THE CWA LATE THIS AFTERNOON INTO THE EVENING HOURS. BOTH 00Z NAM AND 21Z SREF PROBABILITIES INDICATE THE POTENTIAL FOR A RUMBLE OF THUNDER OR TWO OVER THE SOUTHEAST PART OF THE CWA...WHICH CORRELATES WELL WITH POCKET OF STEEPER 850-500MB LAPSE RATES MOVING THROUGH AND BEST FORCING. PREVIOUS SHIFT HAD A SLIGHT CHANCE MENTIONED (WHICH SEEMS REASONABLE) AND ONLY MADE MINOR TWEAKS. ALL OF THE FORCING FEATURES WILL SHIFT NORTHEAST AROUND OR SHORTLY AFTER MIDNIGHT (AND MID LEVEL DRYING OCCURS)...SO HAVE A DIMINISHING TREND TO THE POPS FROM SOUTHWEST TO NORTHEAST. WITH THE DEEP MOISTURE DEPARTING...DID TRANSITION THE PRECIP WORDING FROM RAIN TO DRIZZLE OVERNIGHT (MAINLY OVER THE EASTERN AREAS). MODELS MATCH UP WITH THAT IDEA (BLOTCHY LOOK TO QPF IN THE HIGHER RESOLUTION RUNS). DID CONTINUE TO MENTION SOME FOG WITH THE RAIN THIS EVENING...ALTHOUGH THE WIND MIGHT HELP KEEP IT MORE OF A STRATUS WITH ONLY A SLIGHT LOWERING OF VISIBILITIES EXCEPT OVER THE HIGHER TERRAIN. THUS...HAVE KEPT MOST OF THE AREA UNDER PATCHY WORDING...ALTHOUGH DID IT DIMINISH OVER THE WEST OVERNIGHT AS LOWER LEVEL AIR SLIDES IN. FINALLY...WILL SEE INCREASING SOUTHERLY WINDS TODAY WITH A TIGHTENING PRESSURE GRADIENT BETWEEN THE HIGH OFF THE EAST COAST AND TROUGH MOVING EAST THROUGH MINNESOTA. STRONGEST WINDS WILL BE OVER THE EASTERN CWA...WHERE THE LOW LEVEL JET WILL BE LOCATED. WITH THE INCREASING LOW LEVEL MOISTURE AND EXPECTED CLOUD COVER...THINK THAT WILL LIMIT MIXING AND KEEP WINDS IN CHECK (OCCASIONAL GUSTS IN THE 20-30MPH RANGE SEEN ON BUFKIT MOMENTUM TRANSFER). ABOVE NORMAL TEMPERATURES WILL CONTINUE TODAY AND TONIGHT AS WARM AIR SLIDES NORTH OVER THE AREA. THIS WARM AIR WILL REALLY SURGE IN TONIGHT...WHICH COULD CAUSE MOST LOWS TO OCCUR EARLY THIS EVENING AND THEN RISING OVERNIGHT INTO THE UPPER 40S AND AROUND 50. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 521 AM EST SAT NOV 16 2013 LONG TERM WILL START WITH A STRONG STORM SYSTEM LIFTING THRU THE UPPER GREAT LAKES...BRINGING RAIN AND THEN A TRANSITION TO STRONG WINDS...SNOW SHOWERS AND SEASONABLY COLD AIR. IT STILL LOOKS LIKE A TREND TO LESS AMPLIFIED FLOW TOWARD THE MIDDLE OF NEXT WEEK. THAT MAY ONLY BE SHORT-LIVED AS MEDIUM RANGE GUIDANCE IS NOW INDICATING A SHARPER PROGRESSIVE TROF MOVING ACROSS THE NRN CONUS MID/LATE WEEK RATHER THAN TROF REMAINING MORE CONFINED TO CANADA THAT HAD BEEN INDICATED IN RECENT DAYS MODEL RUNS. END RESULT IS MODERATING TEMPS AND A DRIER PATTERN HEADING INTO MID WEEK AND THEN A TURN TO COLDER WEATHER LATE WEEK...ACCOMPANIED BY SOME -SHSN AND FOLLOWED BY PROBABLY LIGHT LES OFF LAKE SUPERIOR. BEGINNING SUN...ATTENTION WILL BE ON A STRONG SHORTWAVE SWINGING OUT ACROSS THE CNTRL PLAINS. WAVE WILL GO NEGATIVE TILT AND RAPIDLY DEEPEN AS IT PASSES ACROSS THE GREAT LAKES SUN NIGHT. 12HR 500MB HEIGHT FALLS ARE STILL FCST TO MAX OUT AROUND AN IMPRESSIVE 280M TO THE NE AND E OF GEORGIAN BAY. MAJORITY OF GUIDANCE STILL INDICATES DEEPENING SFC LOW LIFTING NE THRU WI AND SE LAKE SUPERIOR...WHICH WAS THE PREFERRED TRACK 24HRS AGO. THE GFS IS STILL THE OUTLIER WITH A FARTHER E TRACK...PASSING ACROSS THE STRAITS AND DRUMMOND ISLAND. IF ANYTHING...THE GFS HAS BEEN TRENDING VERY SLIGHTLY FARTHER S AND E WITH THE TRACK IN RECENT RUNS. WILL CONTINUE TO USE THE MORE CLIMATOLOGICALLY FAVORED SFC LOW TRACK ACROSS FAR SE LAKE SUPERIOR...REPRESENTED BY THE ECMWF/UKMET/GEM AND 4KM NAM WINDOW. INCREASING HEIGHT FALLS AND STRONG UPPER DIFFLUENCE WITH LEFT EXIT OF 130KT UPPER JET NOSING INTO THE GREAT LAKES WILL SUPPORT AN AREA OF SHRA SPREADING N INTO UPPER MI SUN AFTN...WITH THE HEAVIEST PCPN PROBABLY SLIDING THRU CNTRL/ERN UPPER MI LATE AFTN/EVENING WHERE LOW/MID LEVEL FRONTOGENESIS AND ISENTROPIC ASCENT ARE STRONGEST. WITH SHOWALTER INDEX FALLING TO SLIGHTLY NEGATIVE...WILL CONTINUE A MENTION OF THUNDER OVER ROUGHLY THE E HALF OF THE FCST AREA... GENERALLY ALONG AND E OF EXPECTED SFC LOW TRACK. COLDER AIR WRAPPING IN BEHIND THE SYSTEM WILL CHANGE RAIN TO SNOW RATHER QUICKLY FROM W TO E DURING SUN NIGHT PER CONSENSUS OF MODEL THERMAL FIELDS/SOUNDINGS. POTENTIAL FOR HVY SNOW OR EVEN MDT SNOW IS NOTABLY DIMINISHED FROM WHAT SOME MODEL RUNS SUGGESTED IN RECENT DAYS. BIGGEST PROBLEM IS TIMING OF HOW FAST DEFORMATION PCPN SHIELD DEVELOPS/EXPANDS/ORGANIZES ON NW/W SIDE OF SYSTEM. WITH THE FAST SPEED OF SHORTWAVE THRU THE WRN GREAT LAKES AND WITH SFC/MID LEVEL SYSTEM NOT BECOMING WELL DEVELOPED UNTIL NE OF THE AREA...IT DOESN`T APPEAR THE SYNOPTIC SNOW SHIELD WILL BECOME REALLY ORGANIZED UNTIL IT MOVES INTO NRN ONTARIO TO THE N AND NE OF LAKE SUPERIOR. IT WILL PROBABLY TURN INTO A FAIRLY SUBSTANTIAL SNOW STORM FOR AREAS BTWN LAKE SUPERIOR AND JAMES BAY...ESPECIALLY TOWARD JAMES BAY. AS IT APPEARS NOW...THE STEADIER/HEAVIER PCPN IN THE EVENING OVER THE W WILL PROBABLY FALL MOSTLY AS RAIN. BY THE TIME COLUMN COOLS SUFFICIENTLY FOR A CHANGEOVER TO SNOW...THE SYNOPTIC PCPN WILL BE PULLING OUT. STILL...WITH CYCLONIC FLOW/850MB TEMPS FALLING TO AROUND -9C BY 12Z MON AND DEEPER MOISTURE HANGING AROUND...EXPECT LAKE ENHANCED SNOW TO DEVELOP OFF WRN LAKE SUPERIOR OVERNIGHT. MIGHT SEE A FEW INCHES OF SNOW IN THE HIGHER TERRAIN OF THE W BY SUNRISE MON...BUT WITH DENDRITIC SNOW GROWTH TEMPS ABOVE THE UPWARD MOTION ZONE AND POTENTIALLY EVEN ABOVE THE MOIST LAYER...IT MAY BE TOUGH TO GET A FEW INCHES OF SNOW. STRONG BOUNDARY LAYER WINDS SHOULD TEND TO SPREAD THE LAKE ENHANCED SNOW A BIT FARTHER INLAND THAN IS USUALLY THE CASE. HURON MTNS MAY BE AN AREA TO SEE MOST PERISTENT SNOWFALL. LATE CHANGEOVER TO SNOW OVER THE E WILL FURTHER LIMIT SNOW ACCUMULATIONS IN THAT AREA SUN NIGHT. NO HEADLINES PERTAINING TO SNOW ARE WARRANTED AT THIS TIME. WINDS WILL BE A BIG STORY WITH THE SYSTEM. IN THE WAKE OF THE DEEPENING SFC LOW...MODELS INDICATE NW WINDS OF 45-55KT AT 850MB DURING THE PERIOD OF CAA. 4KM HIGH RES NAM SHOWS WIND GUST POTENTIAL TO A LITTLE OVER 40KT OVER THE KEWEENAW AND TO A LITTLE OVER 50KT ALONG THE LAKESHORE E OF MARQUETTE. ISALLOBARIC WIND COMPONENT WILL ADD SOME ENHANCEMENT AS PRES RISES STRENGTHEN OVER THE AREA IN THE WAKE OF THE DEEPENING LOW. IF ADVY HEADLINES END UP NOT BEING NEEDED FOR SNOWFALL...WIND HEADLINES WILL BE NEEDED. ON LAKE SUPERIOR... HIGH GALES ARE LIKELY ON THE E HALF OF LAKE SUPERIOR WITH DECENT POTENTIAL FOR A PERIOD OF STORM FORCE WINDS LATE OVERNIGHT SUN NIGHT INTO MON MORNING. TRANSITION TO PURE LES WILL OCCUR MON/MON NIGHT UNDER NW FLOW AS 850MB TEMPS FALL TO -10/-11C. LINGERING LIGHT LES WILL WIND DOWN/END OVER WRN UPPER MI MON NIGHT AND OVER NCNTRL UPPER MI TUE MORNING AS AS FLOW BACKS AND WAA GETS UNDERWAY. WITH SFC HIGH PRES RIDGE REACHING WRN UPPER MI LATE MON NIGHT...TEMPS COULD PLUMMET IF CLOUDS CLEAR OUT. NONE OF THE GUIDANCE IS ESPECIALLY COLD. LOWEST GUIDANCE GENERALLY SUGGEST MINS IN THE UPPER TEENS...AND FCST WILL REFLECT THESE COLDER NUMBERS. WAA WED MIGHT YIELD SOME LIGHT PCPN AT THAT TIME. THEN...STRONG SHORTWAVE MOVING ACROSS SRN CANADA WILL SWEEP ASSOCIATED COLD FRONT ACROSS THE AREA WED NIGHT...ACCOMPANIED BY SOME -RA/-SN. LES MAY GET UNDERWAY THU...BUT MODELS HAVE NOT BEEN VERY CONSISTENT ON THE INTENSITY OF THE COLD FOLLOWING THE FRONT. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 121 PM EST SAT NOV 16 2013 ON FAVORABLE S WINDS WITH APPROACHING LOW LEVEL MOISTURE...CEILINGS AT SAW QUICKLY FELL INTO THE IFR CATEGORY ...WHERE THEY WILL PRETTY MUCH STAY /IFR TO LIFR/ THROUGH SUNDAY MORNING. AT THE OTHER SITES...THE LOWER CLOUDS HAVE BEEN SLOWER TO ARRIVE...WITH IFR OR MVFR CEILINGS EXPECTED TO SET IN THROUGH 09Z SUNDAY. SAW IS CLOSE TO LLWS CRITERIA FROM 23Z SATURDAY THROUGH 06Z SUNDAY. HOWEVER...WITH SFC WINDS STAYING UP WITH GUSTS ON THE ORDER OF 20-25KTS...WILL EXCLUDE THE MENTION OF LLWS AT THIS TIME. RAIN WILL BE THE MAIN WEATHER TYPE. LOOKING FARTHER AHEAD...EXPECT STRONG NW WINDS TO PUSH IN BEHIND THE EXITING SFC LOW AFTER 00Z MONDAY. THE STRONGEST WINDS WITH GUSTS NEAR 30KTS AT CMX AND TO A LESS EXTENT SAW...CONTINUING THROUGH MID MORNING MONDAY. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 340 PM EST SAT NOV 16 2013 GALE AND STORM FORCE WIND WATCHES REMAIN IN PLACE FOR MUCH OF LAKE SUPERIOR FOR LATE SUNDAY EVENING THROUGH MONDAY MORNING. LOW PRESSURE OVER SOUTHERN MINNESOTA WILL SWING ACROSS WESTERN LAKE SUPERIOR SUNDAY MORNING...WHILE AN ADDITIONAL LOW TO THE SOUTH NEARS FROM THE SOUTHWEST. EXPECT THE LOWS TO COMBINE AND DEEPEN SIGNIFICANTLY ACROSS FAR EASTERN LAKE SUPERIOR BY LATE SUNDAY AFTERNOON...BEFORE EXITING NORTHEASTWARD TO JUST EAST OF JAMES BAY MONDAY AFTERNOON. NW GALE TO STORM FORCE REMAIN POSSIBLE OVER MUCH OF LAKE SUPERIOR LATE SUNDAY EVENING THROUGH MONDAY MORNING...WITH GALES EXTENDING THROUGH EARLY MONDAY EVENING ACROSS THE E HALF OF LAKE SUPERIOR. HIGH PRESSURE STRETCHING FROM CENTRAL CANADA THROUGH THE SOUTHERN PLAINS MONDAY WILL SLIDE ACROSS THE UPPER GREAT LAKES MONDAY NIGHT AND TUESDAY. BEHIND THE EXITING HIGH...LOW PRESSURE ALONG THE WESTERN U.S. AND CANADIAN BORDER ON TUESDAY WILL CROSS LAKE WINNIPEG TUESDAY NIGHT INCHES...AND EXIT NORTHEAST ACROSS HUDSON BAY WEDNESDAY INTO WEDNESDAY NIGHT WHILE DRAGGING A TROUGH ACROSS LAKE SUPERIOR. EXPECT STRONG HIGH PRESSURE ACROSS THE PLAINS STATES THURSDAY MORNING TO BUILD ACROSS THE UPPER GREAT LAKES BY THURSDAY NIGHT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... HIGH WIND WATCH FROM SUNDAY EVENING THROUGH MONDAY AFTERNOON FOR MIZ001-006-007. LAKE SUPERIOR... STORM WATCH FROM SUNDAY EVENING THROUGH MONDAY AFTERNOON FOR LSZ244-245-248>251-264>267. GALE WATCH FROM SUNDAY EVENING THROUGH MONDAY AFTERNOON FOR LSZ241>243-263. LAKE MICHIGAN... GALE WATCH FROM SUNDAY EVENING THROUGH MONDAY MORNING FOR LMZ221- 248-250. && $$ SHORT TERM...SRF LONG TERM...ROLFSON AVIATION...KF MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
123 PM EST SAT NOV 16 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 521 AM EST SAT NOV 16 2013 SOUTHWESTERLY FLOW IS BEGINNING TO INCREASE OVER THE CWA AS THE UPPER TROUGH AMPLIFIES DUE TO A STRONG SHORTWAVE MOVING SOUTHEAST THROUGH THE PACIFIC NORTHWEST. THIS SHORTWAVE WILL BE THE MAJOR PLAYER TO OUR WEATHER FOR THE SECOND HALF OF THE WEEKEND. FOR THE SHORT TERM...THE SOUTHWESTERLY FLOW ALOFT WILL ALLOW A SHORTWAVE CURRENTLY LOCATED NEAR THE FOUR CORNERS REGION TO MOVE NORTHEAST ACROSS THE UPPER GREAT LAKES LATE THIS AFTERNOON AND EVENING. MOISTURE STREAMING NORTHEAST ON WV IMAGERY IS LEADING TO SOME HIGH CLOUDS OVER MUCH OF UPPER MICHIGAN. IN THE LOWER LEVELS...INITIAL RAP SOUNDINGS SHOWING PLENTY OF DRY AIR BELOW THE HIGH CLOUDS BUT THERE WAS ENOUGH RADIATIONAL COOLING EARLIER THIS EVENING TO PRODUCE SOME PATCHY FOG OVER CENTRAL/EASTERN UPPER MICHIGAN. THE DRIER LOW LEVELS WILL LIKELY BE SHORT LIVED AS 3-5KFT CEILINGS COVER MUCH OF CENTRAL/NORTHERN WISCONSIN AND WILL BE MOVING INTO THE AREA OVER THE NEXT COUPLE OF HOURS. IN ADDITION TO THOSE CLOUDS...MODELS ARE SHOWING THE DEVELOPING 1KFT CEILINGS IN NORTHERN ILLINOIS TO QUICKLY LIFT NORTH AND EXPAND THIS MORNING AND EARLY AFTERNOON...COVERING MUCH OF UPPER MICHIGAN. THE SHORTWAVE WILL BE NEARING THE REGION THIS AFTERNOON AND THERE ARE SEVERAL FEATURES SUPPORTING A BROAD AREA OF RAIN MOVING THROUGH THE AREA LATE THIS AFTERNOON AND EVENING. FIRST...EXPECT THERE TO BE A WEAK COUPLED JET STRUCTURE OVER THE AREA THIS EVENING. BROAD MID LEVEL WARM AIR ADVECTION AND MOISTURE TRANSPORT WILL ACCOMPANY THIS SHORTWAVE...WITH THE EASTERN CWA SEEING THE BEST OF BOTH FEATURES. AT THE SURFACE...THE BROAD LOW DEVELOPING OVER THE CENTRAL/NORTHERN PLAINS WILL SLIDE A TROUGH THROUGH MINNESOTA TODAY AND OVER WESTERN LAKE SUPERIOR TONIGHT. HAVE HIGH CONFIDENCE IN THE FORECAST FOR THIS AFTERNOON/EVENING BASED OFF GREAT MODEL CONSISTENCY. SINCE THE BEST FORCING IS OVER THE SOUTHEAST HALF...WILL HAVE THE HIGHEST POPS/QPF IN THAT AREA BUT THERE WILL BE A PERIOD OF DEFINITE POPS OVER THE ENTIRE AREA. AS FOR QPF...EXPECT VALUES TO RANGE FROM 0.2 OVER THE WEST TO 0.75IN OVER THE EAST...WITH SOME HIGHER AMOUNTS IF THERE ARE SOME EMBEDDED THUNDERSTORMS. AS FOR THUNDER...THERE IS A POCKET OF 50-125J/KG OF MUCAPE AND SHOWALTER VALUES SLIGHTLY BELOW 0 OVER THE EASTERN 2/3RDS OF THE CWA LATE THIS AFTERNOON INTO THE EVENING HOURS. BOTH 00Z NAM AND 21Z SREF PROBABILITIES INDICATE THE POTENTIAL FOR A RUMBLE OF THUNDER OR TWO OVER THE SOUTHEAST PART OF THE CWA...WHICH CORRELATES WELL WITH POCKET OF STEEPER 850-500MB LAPSE RATES MOVING THROUGH AND BEST FORCING. PREVIOUS SHIFT HAD A SLIGHT CHANCE MENTIONED (WHICH SEEMS REASONABLE) AND ONLY MADE MINOR TWEAKS. ALL OF THE FORCING FEATURES WILL SHIFT NORTHEAST AROUND OR SHORTLY AFTER MIDNIGHT (AND MID LEVEL DRYING OCCURS)...SO HAVE A DIMINISHING TREND TO THE POPS FROM SOUTHWEST TO NORTHEAST. WITH THE DEEP MOISTURE DEPARTING...DID TRANSITION THE PRECIP WORDING FROM RAIN TO DRIZZLE OVERNIGHT (MAINLY OVER THE EASTERN AREAS). MODELS MATCH UP WITH THAT IDEA (BLOTCHY LOOK TO QPF IN THE HIGHER RESOLUTION RUNS). DID CONTINUE TO MENTION SOME FOG WITH THE RAIN THIS EVENING...ALTHOUGH THE WIND MIGHT HELP KEEP IT MORE OF A STRATUS WITH ONLY A SLIGHT LOWERING OF VISIBILITIES EXCEPT OVER THE HIGHER TERRAIN. THUS...HAVE KEPT MOST OF THE AREA UNDER PATCHY WORDING...ALTHOUGH DID IT DIMINISH OVER THE WEST OVERNIGHT AS LOWER LEVEL AIR SLIDES IN. FINALLY...WILL SEE INCREASING SOUTHERLY WINDS TODAY WITH A TIGHTENING PRESSURE GRADIENT BETWEEN THE HIGH OFF THE EAST COAST AND TROUGH MOVING EAST THROUGH MINNESOTA. STRONGEST WINDS WILL BE OVER THE EASTERN CWA...WHERE THE LOW LEVEL JET WILL BE LOCATED. WITH THE INCREASING LOW LEVEL MOISTURE AND EXPECTED CLOUD COVER...THINK THAT WILL LIMIT MIXING AND KEEP WINDS IN CHECK (OCCASIONAL GUSTS IN THE 20-30MPH RANGE SEEN ON BUFKIT MOMENTUM TRANSFER). ABOVE NORMAL TEMPERATURES WILL CONTINUE TODAY AND TONIGHT AS WARM AIR SLIDES NORTH OVER THE AREA. THIS WARM AIR WILL REALLY SURGE IN TONIGHT...WHICH COULD CAUSE MOST LOWS TO OCCUR EARLY THIS EVENING AND THEN RISING OVERNIGHT INTO THE UPPER 40S AND AROUND 50. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 521 AM EST SAT NOV 16 2013 LONG TERM WILL START WITH A STRONG STORM SYSTEM LIFTING THRU THE UPPER GREAT LAKES...BRINGING RAIN AND THEN A TRANSITION TO STRONG WINDS...SNOW SHOWERS AND SEASONABLY COLD AIR. IT STILL LOOKS LIKE A TREND TO LESS AMPLIFIED FLOW TOWARD THE MIDDLE OF NEXT WEEK. THAT MAY ONLY BE SHORT-LIVED AS MEDIUM RANGE GUIDANCE IS NOW INDICATING A SHARPER PROGRESSIVE TROF MOVING ACROSS THE NRN CONUS MID/LATE WEEK RATHER THAN TROF REMAINING MORE CONFINED TO CANADA THAT HAD BEEN INDICATED IN RECENT DAYS MODEL RUNS. END RESULT IS MODERATING TEMPS AND A DRIER PATTERN HEADING INTO MID WEEK AND THEN A TURN TO COLDER WEATHER LATE WEEK...ACCOMPANIED BY SOME -SHSN AND FOLLOWED BY PROBABLY LIGHT LES OFF LAKE SUPERIOR. BEGINNING SUN...ATTENTION WILL BE ON A STRONG SHORTWAVE SWINGING OUT ACROSS THE CNTRL PLAINS. WAVE WILL GO NEGATIVE TILT AND RAPIDLY DEEPEN AS IT PASSES ACROSS THE GREAT LAKES SUN NIGHT. 12HR 500MB HEIGHT FALLS ARE STILL FCST TO MAX OUT AROUND AN IMPRESSIVE 280M TO THE NE AND E OF GEORGIAN BAY. MAJORITY OF GUIDANCE STILL INDICATES DEEPENING SFC LOW LIFTING NE THRU WI AND SE LAKE SUPERIOR...WHICH WAS THE PREFERRED TRACK 24HRS AGO. THE GFS IS STILL THE OUTLIER WITH A FARTHER E TRACK...PASSING ACROSS THE STRAITS AND DRUMMOND ISLAND. IF ANYTHING...THE GFS HAS BEEN TRENDING VERY SLIGHTLY FARTHER S AND E WITH THE TRACK IN RECENT RUNS. WILL CONTINUE TO USE THE MORE CLIMATOLOGICALLY FAVORED SFC LOW TRACK ACROSS FAR SE LAKE SUPERIOR...REPRESENTED BY THE ECMWF/UKMET/GEM AND 4KM NAM WINDOW. INCREASING HEIGHT FALLS AND STRONG UPPER DIFFLUENCE WITH LEFT EXIT OF 130KT UPPER JET NOSING INTO THE GREAT LAKES WILL SUPPORT AN AREA OF SHRA SPREADING N INTO UPPER MI SUN AFTN...WITH THE HEAVIEST PCPN PROBABLY SLIDING THRU CNTRL/ERN UPPER MI LATE AFTN/EVENING WHERE LOW/MID LEVEL FRONTOGENESIS AND ISENTROPIC ASCENT ARE STRONGEST. WITH SHOWALTER INDEX FALLING TO SLIGHTLY NEGATIVE...WILL CONTINUE A MENTION OF THUNDER OVER ROUGHLY THE E HALF OF THE FCST AREA... GENERALLY ALONG AND E OF EXPECTED SFC LOW TRACK. COLDER AIR WRAPPING IN BEHIND THE SYSTEM WILL CHANGE RAIN TO SNOW RATHER QUICKLY FROM W TO E DURING SUN NIGHT PER CONSENSUS OF MODEL THERMAL FIELDS/SOUNDINGS. POTENTIAL FOR HVY SNOW OR EVEN MDT SNOW IS NOTABLY DIMINISHED FROM WHAT SOME MODEL RUNS SUGGESTED IN RECENT DAYS. BIGGEST PROBLEM IS TIMING OF HOW FAST DEFORMATION PCPN SHIELD DEVELOPS/EXPANDS/ORGANIZES ON NW/W SIDE OF SYSTEM. WITH THE FAST SPEED OF SHORTWAVE THRU THE WRN GREAT LAKES AND WITH SFC/MID LEVEL SYSTEM NOT BECOMING WELL DEVELOPED UNTIL NE OF THE AREA...IT DOESN`T APPEAR THE SYNOPTIC SNOW SHIELD WILL BECOME REALLY ORGANIZED UNTIL IT MOVES INTO NRN ONTARIO TO THE N AND NE OF LAKE SUPERIOR. IT WILL PROBABLY TURN INTO A FAIRLY SUBSTANTIAL SNOW STORM FOR AREAS BTWN LAKE SUPERIOR AND JAMES BAY...ESPECIALLY TOWARD JAMES BAY. AS IT APPEARS NOW...THE STEADIER/HEAVIER PCPN IN THE EVENING OVER THE W WILL PROBABLY FALL MOSTLY AS RAIN. BY THE TIME COLUMN COOLS SUFFICIENTLY FOR A CHANGEOVER TO SNOW...THE SYNOPTIC PCPN WILL BE PULLING OUT. STILL...WITH CYCLONIC FLOW/850MB TEMPS FALLING TO AROUND -9C BY 12Z MON AND DEEPER MOISTURE HANGING AROUND...EXPECT LAKE ENHANCED SNOW TO DEVELOP OFF WRN LAKE SUPERIOR OVERNIGHT. MIGHT SEE A FEW INCHES OF SNOW IN THE HIGHER TERRAIN OF THE W BY SUNRISE MON...BUT WITH DENDRITIC SNOW GROWTH TEMPS ABOVE THE UPWARD MOTION ZONE AND POTENTIALLY EVEN ABOVE THE MOIST LAYER...IT MAY BE TOUGH TO GET A FEW INCHES OF SNOW. STRONG BOUNDARY LAYER WINDS SHOULD TEND TO SPREAD THE LAKE ENHANCED SNOW A BIT FARTHER INLAND THAN IS USUALLY THE CASE. HURON MTNS MAY BE AN AREA TO SEE MOST PERISTENT SNOWFALL. LATE CHANGEOVER TO SNOW OVER THE E WILL FURTHER LIMIT SNOW ACCUMULATIONS IN THAT AREA SUN NIGHT. NO HEADLINES PERTAINING TO SNOW ARE WARRANTED AT THIS TIME. WINDS WILL BE A BIG STORY WITH THE SYSTEM. IN THE WAKE OF THE DEEPENING SFC LOW...MODELS INDICATE NW WINDS OF 45-55KT AT 850MB DURING THE PERIOD OF CAA. 4KM HIGH RES NAM SHOWS WIND GUST POTENTIAL TO A LITTLE OVER 40KT OVER THE KEWEENAW AND TO A LITTLE OVER 50KT ALONG THE LAKESHORE E OF MARQUETTE. ISALLOBARIC WIND COMPONENT WILL ADD SOME ENHANCEMENT AS PRES RISES STRENGTHEN OVER THE AREA IN THE WAKE OF THE DEEPENING LOW. IF ADVY HEADLINES END UP NOT BEING NEEDED FOR SNOWFALL...WIND HEADLINES WILL BE NEEDED. ON LAKE SUPERIOR... HIGH GALES ARE LIKELY ON THE E HALF OF LAKE SUPERIOR WITH DECENT POTENTIAL FOR A PERIOD OF STORM FORCE WINDS LATE OVERNIGHT SUN NIGHT INTO MON MORNING. TRANSITION TO PURE LES WILL OCCUR MON/MON NIGHT UNDER NW FLOW AS 850MB TEMPS FALL TO -10/-11C. LINGERING LIGHT LES WILL WIND DOWN/END OVER WRN UPPER MI MON NIGHT AND OVER NCNTRL UPPER MI TUE MORNING AS AS FLOW BACKS AND WAA GETS UNDERWAY. WITH SFC HIGH PRES RIDGE REACHING WRN UPPER MI LATE MON NIGHT...TEMPS COULD PLUMMET IF CLOUDS CLEAR OUT. NONE OF THE GUIDANCE IS ESPECIALLY COLD. LOWEST GUIDANCE GENERALLY SUGGEST MINS IN THE UPPER TEENS...AND FCST WILL REFLECT THESE COLDER NUMBERS. WAA WED MIGHT YIELD SOME LIGHT PCPN AT THAT TIME. THEN...STRONG SHORTWAVE MOVING ACROSS SRN CANADA WILL SWEEP ASSOCIATED COLD FRONT ACROSS THE AREA WED NIGHT...ACCOMPANIED BY SOME -RA/-SN. LES MAY GET UNDERWAY THU...BUT MODELS HAVE NOT BEEN VERY CONSISTENT ON THE INTENSITY OF THE COLD FOLLOWING THE FRONT. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 121 PM EST SAT NOV 16 2013 ON FAVORABLE S WINDS WITH APPROACHING LOW LEVEL MOISTURE...CEILINGS AT SAW QUICKLY FELL INTO THE IFR CATEGORY ...WHERE THEY WILL PRETTY MUCH STAY /IFR TO LIFR/ THROUGH SUNDAY MORNING. AT THE OTHER SITES...THE LOWER CLOUDS HAVE BEEN SLOWER TO ARRIVE...WITH IFR OR MVFR CEILINGS EXPECTED TO SET IN THROUGH 09Z SUNDAY. SAW IS CLOSE TO LLWS CRITERIA FROM 23Z SATURDAY THROUGH 06Z SUNDAY. HOWEVER...WITH SFC WINDS STAYING UP WITH GUSTS ON THE ORDER OF 20-25KTS...WILL EXCLUDE THE MENTION OF LLWS AT THIS TIME. RAIN WILL BE THE MAIN WEATHER TYPE. LOOKING FARTHER AHEAD...EXPECT STRONG NW WINDS TO PUSH IN BEHIND THE EXITING SFC LOW AFTER 00Z MONDAY. THE STRONGEST WINDS WITH GUSTS NEAR 30KTS AT CMX AND TO A LESS EXTENT SAW...CONTINUING THROUGH MID MORNING MONDAY. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 521 AM EST SAT NOV 16 2013 SOUTH WINDS WILL INCREASE TO 30KT TODAY AHEAD OF DEEPENING SFC LOW MOVING FROM THE PLAINS TOWARD THE UPPER MISSISSIPPI VALLEY. STRONGEST WINDS TODAY/TONIGHT WILL BE OVER EASTERN PORTIONS OF LAKE SUPERIOR...WHERE THERE MAY BE A FEW GALE GUSTS TO 35KT. STABLE LOW-LEVEL TEMPERATURE PROFILE AND LACK OF PRESSURE FALLS TO NORTH OF LAKE SUPERIOR SHOULD LIMIT FREQUENCY OF GUSTS. WINDS WILL DIMINISH FOR A TIME SUNDAY AS SFC TROF DRIFTS OVERHEAD AND PRES GRADIENT WEAKENS CONSIDERABLY. NEW LOW PRESSURE ORGANIZING OVER THE PLAINS WILL THEN LIFT NE ALONG THE TROF AND RAPIDLY DEEPEN AS IT PASSES ACROSS FAR SE LAKE SUPERIOR INTO NRN ONTARIO. PRES WILL LIKELY FALL BLO 975MB OR 29.0 INCHES AS IT MOVES N OF THE LAKE SUNDAY NIGHT/MON MORNING. IN THE NW FLOW IN THE WAKE OF THE DEEPENING LOW PRES... GALES WILL OCCUR ACROSS ALL BUT FAR WRN LAKE SUPERIOR WITH HIGH END GALES TO STORM FORCE WINDS LIKELY SUN NIGHT/MON MORNING OVER THE E HALF. GIVEN STORM POTENTIAL...A STORM WATCH HAS BEEN ISSUED FOR THE E HALF OF LAKE SUPERIOR. WINDS WILL DIMINISH BELOW 30KT FROM W TO E MON NIGHT...AND A PERIOD OF LIGHT WINDS UNDER 15KT SHOULD OCCUR TUE AS HIGH PRES RIDGE PASSES ACROSS LAKE SUPERIOR. S WINDS WILL THEN RAMP UP TO 20-30KT FOR WED BEHIND THE HIGH AND AHEAD OF THE NEXT APPROACHING LOW PRES TROF. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... STORM WATCH FROM SUNDAY EVENING THROUGH MONDAY AFTERNOON FOR LSZ248>251-265>267. GALE WATCH FROM SUNDAY EVENING THROUGH MONDAY AFTERNOON FOR LSZ241>245-263-264. LAKE MICHIGAN... GALE WATCH FROM SUNDAY EVENING THROUGH MONDAY MORNING FOR LMZ221- 248-250. && $$ SHORT TERM...SRF LONG TERM...ROLFSON AVIATION...KF MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
322 PM CST SAT NOV 16 2013 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 240 PM CST SAT NOV 16 2013 FIRST WAVE OF -RA/-DZ...AND EVEN A FEW THUNDERSTORMS THAT DEVELOPED ALONG THE LEADING EDGE OF THE STRONG VERTICAL LIFT ACROSS EC/SC MN EARLIER THIS AFTN. VISIBLE SATELLITE IMAGERY THIS AFTN INDICATED THE DRIER AIR MOVING ACROSS NW IOWA WHICH WILL IMPACT FAR SOUTHERN MN THIS EVENING. SOME BREAKS IN THE CLD CVR ARE LIKELY WITH THIS AREA OF DRIER AIR...BUT HOW FAR NORTH THIS CLEARING DEVELOPS REMAINS UNCERTAIN. LATEST RAP HAS AREAS SOUTH OF HWY 212 REMAINING NEARLY SATURATED BLW 2K THRU TONIGHT. DEEP SFC LOW IN NE SD WILL SLOWLY MOVE ENE ACROSS CENTRAL MN THIS EVENING...AND THEN ACROSS NE MN BY SUNDAY MORNING. THIS WILL KEEP MOST OF CENTRAL MN IN A WEAK FLOW IN THE BOUNDARY LAYER AND THEREFORE KEEPING LOW CLDS/FOG AND OCCASIONAL DRIZZLE IN THE FORECAST. NEXT SHRTWV OF INTEREST WILL IMPACT MAINLY THE SE CWA WITH -RA SUNDAY MORNING...INTO THE EARLY AFTN. FURTHER TO THE NW...THERE REMAINS ENOUGH ENERGY TO KEEP LOW POPS OVERNIGHT...BUT WITH CAA ANY PRECIPITATION AMTS WILL REMAIN LIGHT. SOME -SN/FLURRIES ARE POSSIBLE SUNDAY AFTN BEFORE ANY LEFTOVER PRECIPITATION ENDS ACROSS CENTRAL MN...BUT NOT CONFIDENT ENOUGH TO INCLUDE IN THIS FORECAST PACKAGE. TEMPS MAY BE A BIT LOWER IN FAR SOUTHERN MN IF SKIES CLR. THE LOW CLDS/FOG AND DRIZZLE WILL KEEP THE REST OF THE CWA WITH LITTLE TEMP CHG UNTIL SUNDAY AS WINDS SHIFT TO THE W/NW AND BEGIN TO GUST. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 240 PM CST SAT NOV 16 2013 DRIER AIR SHOULD FOLLOW THE FROPA QUICKLY SUNDAY NIGHT WITH CLEARING SKIES INTO MONDAY. MODELS CONTINUE TO ADVERTISE A SIDESWIPING OF THE TROUGH MONDAY BEFORE IMPRESSIVE RIDGING RETURNS TUESDAY AND WEDNESDAY. INCREASED TEMPS A DEGREE OR TWO MONDAY AND MONDAY NIGHT...BUT SEVERAL DEGREES TUESDAY AS 925 MB TEMPS OF +4C TO +8C PUSH INTO THE CWA. MIXING TO THAT LEVEL WOULD YIELD HIGHS IN THE MID/UPPER 50S OVER SOUTHERN MN AND UPPER 40S OVER WRN WI. DID NOT QUITE GO THAT HIGH YET SINCE THIS IS A RELATIVELY NEW MODEL TREND...BUT EACH OF THE LAST SEVERAL RUNS HAVE BEEN GETTING PROGRESSIVELY WARMER. MODEL CONSISTENCY HAS IMPROVED TODAY WITH A DRY COLD FRONT PROGGED TO PUSH THROUGH LATE WEDNESDAY OR WEDNESDAY NIGHT. THERMAL RIDGING IN ADVANCE OF THE FRONT WILL KEEP TEMPERATURES MILD TUESDAY NIGHT AND WEDNESDAY. A 1040 MB HIGH WILL BUILD IN BEHIND THE FRONT...BUT MODELS DIFFER A BIT WHERE THIS WILL TRACK WHICH WILL DETERMINE THE DEGREE OF COLD AIR LATE NEXT WEEK. AN INVERTED TROUGH PUSHING THROUGH THURSDAY NIGHT OR FRIDAY MAY BRING A COATING OF SNOW TO THE REGION. INTRODUCED LOW POPS FOR NOW DURING THIS PERIOD. AN INTERESTING DEVELOPMENT HAS EMERGED ON THE 12Z ECMWF AND CANADIAN FOR NEXT WEEKEND. FOLLOWING THE INVERTED TROUGH...A PROLIFIC 1050-1055MB HIGH BUILDING INTO THE NORTHERN ROCKIES/NORTHWESTERN PLAINS COULD BRING OUR FIRST SHOT AT VERY COLD TEMPERATURES. HOWEVER...THE GFS AND FIM MAINTAIN A MUCH MILDER SOLUTION WITH A WEAKER AND MORE PROGRESSIVE HIGH REMAINING IN CANADA SO CANNOT TREND TOWARD EITHER SOLUTION YET. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 1127 AM CST SAT NOV 16 2013 MPX TAFS STARTING OUT WITH IFR/LIFR CIGS/VSBYS WHICH MAY IMPROVE SOME DURING THE AFTN WITH MIXING OF -RA...BUT STILL REMAINING BLW 1K. HOWEVER...NOT UNTIL DRIER AIR ADVECTS FROM THE SW ACROSS IA/NE WILL WE SEE ANY SIGNIFICANT IMPROVEMENTS. THE WORSE TIME FRAME WILL OCCUR IN THE FIRST 3 HRS WITH SOME POSSIBILITY OF TSRA AT KRWF/KEAU DUE TO INCREASING CONVECTION NOTED IN THESE AREAS. ALTHOUGH KRWF/KRHN/KEAU MAY SEE CIGS LIFT DURING THE EVENING HRS TO MVFR...NOT TOO OPTIMISTIC UNTIL WINDS SHIFT AND INCREASE FROM THE SW. LOW CONFIDENCE ON MVFR CIGS DEVELOPING THIS AFTN/EVENING. AFT 3-6Z...WENT WITH A MORE IFR/LIFR CIGS/VSBYS AT KAXN/KSTC DUE TO WEAK SFC WINDS AND MIXING IN THE BOUNDARY LAYER...PLUS THE ADDED MOISTURE FROM -RA/-DZ THIS AFTN. ELSEWHERE...WILL CONTINUE WITH SOME IMPROVEMENT IN THE EVENING...BUT LOWER THE CIGS ONCE AGAIN AFT 6Z...THEN INCREASE THE CIGS/VSBYS AFT 12-15Z. WINDS WILL REMAIN FROM THE S/SE THIS AFTN...THEN MORE S/SW THIS EVENING...BECOMING MORE W/NW BY SUNDAY MORNING/AFTN. KMSP... KEPT THE LOWER CIGS THRU THE AFTN AND EVENING WITH VSBYS LOWERING TO 2SM IN -RA/-DZ AT TIMES. ALTHOUGH REGIONAL RADAR DOES NOT HAVE ANYTHING WIDESPREAD...BELIEVE IN THE NEXT HR OR TWO...PRECIPITATION WILL EXPAND WITH HEAVIER ACTIVITY POSSIBLE 19-21Z WHERE BOTH THE BEST LIFT AND DEEPER MOISTURE RESIDES. MORE OF A DRIZZLE SCENARIO AFT 21-22Z...WITH DRIER AIR ADVECTING FROM THE SW THIS EVENING. KEPT CIGS IFR...BUT MVFR CIGS MAY DEVELOP DURING THE 02-04Z TIME FRAME. MVFR/VFR CIGS CONTINUE THRU SUNDAY MORNING WITH VFR CONDS DEVELOPING SUNDAY AFTN AS WINDS INCREASE FROM THE NW. CONFIDENCE REMAINS HIGH FOR THE CONTINUED IFR CIGS THIS AFTN...CONFIDENCES LOWERS WITH MVFR CIGS DEVELOPING THIS EVENING/OVERNIGHT. /OUTLOOK FOR KMSP/ MON...MVFR CIGS EARLY. THEN VFR. WINDS WNW AT 10G15KTS. TUE...VFR. WINDS SE AT 10KTS. WED...VFR WITH MVFR AND -RA LATE. WINDS SSW AT 10G15KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...JLT LONG TERM...BORGHOFF AVIATION...JLT
AREA FORECAST DISCUSSION
NWS GLASGOW MT
349 PM MST SAT NOV 16 2013 .SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH MONDAY... SHORT TERM MODEL SOLUTIONS CONTINUE TO BE OF VERY LITTLE HELP AND SIGNIFICANT SNOW FALL AMOUNT AND PLACEMENT DISCREPANCIES ABOUND. FORECAST CHALLENGES WILL FOCUS ON TRYING TO WORK OUT THESE TWO PROBLEMS THROUGH SUNDAY. OF MOST HELP WILL LIKELY BE COMPARING RADAR IMAGERY WITH MODEL SOLUTIONS TO SEE WHICH ONE IS PERFORMING THE BEST AND TRY TO LEAN WITH OR TRUST THAT ONE MORE THAN THE OTHERS. AT THE ONSET OF THIS SYSTEM...THE HRRR MODEL SEEMS TO BE PERFORMING THE BEST. ENOUGH ACCUMULATING SNOW SEEMS LIKELY TO SNEAK ACROSS THE INTERNATIONAL BORDER TO ACCUMULATE AROUND 2 INCHES FOR OUR NORTHEASTERN ZONES. WENT AHEAD AND ISSUED A WINTER WEATHER ADVISORY FOR SHERIDAN AND EASTERN ROOSEVELT COUNTIES. MOST OTHER LOCATIONS WILL PROBABLY RECEIVE AROUND 1 INCH OF SNOW. ALTHOUGH SOME MODELS SHOWED POST-FRONTAL WINDS BELOW 15 KNOTS...ALL NEAR SHORT-TERM AND HIGH-RESOLUTION MODELS ARE IN AGREEMENT SHOWING STRONG AND GUSTY WEST-NORTHWESTERLY WINDS PUSHING INTO THE AREA AFTER MIDNIGHT TONIGHT. CHOSE TO ISSUE A LAKE WIND ADVISORY FROM AFTER MIDNIGHT TONIGHT THROUGH THE DAY ON SUNDAY. BY SUNDAY NIGHT...THE LARGE UPPER-LEVEL TROUGH PIVOTS EASTWARD...PARTIALLY CLEARING OUR SKIES AND DRIVING ANY PRECIPITATION AWAY AS THE FLOW ALOFT TURNS MORE ZONAL. AFTER A GOOD HARD FREEZE TONIGHT AND SUNDAY NIGHT...TEMPERATURES WILL EASILY REBOUND TO MORE NORMAL VALUES FOR THIS TIME OF YEAR. BMICKELSON .LONG TERM...MONDAY NIGHT THROUGH SATURDAY... GOING FORECAST IS IN OVERALL GOOD SHAPE. MODELS CONTINUE TO AGREE IN A SHORTWAVE PASSAGE LATE TUESDAY INTO WEDNESDAY. MODELS REMAIN RELATIVELY DRY WITH THIS FEATURE...BUT WE CONSERVATIVELY TRENDED UP POPS GIVEN DECENT CONSISTENCY. MODEL DIFFERENCES ARE PRESENT FOR NEXT FRIDAY INTO SATURDAY. THE GFS AND DGEX ARE WARMER...BUILDING IN WEAK RIDGING BEHIND THE EXITING UPPER TROUGH. THE ECMWF AND GEM BOTH DROP ANOTHER UPPER TROUGH THROUGH WITH ANOTHER BLAST OF ARCTIC AIR. CONTINUED TO LEAN MORE ON THE SIDE OF THE COOLER ECMWF AND GEM DUE TO THEIR RECENT BETTER PERFORMANCE...BUT REMAIN MUCH WARMER THEN THE OPERATIONAL RUNS. GILCHRIST PREVIOUS LONG TERM DISCUSSION...TUESDAY WILL BE MILD AND DRY WITH ZONAL FLOW ALOFT. SHORTWAVE UPPER TROUGH MOVES THROUGH MONTANA ON WEDNESDAY AND DRAGS A STRONG COLD FRONT SOUTH. THE SYSTEM HAS LIMITED MOISTURE SO THAT THE ANY PRECIPITATION THAT OCCURS WILL BE MAINLY ALONG THE FRONT. MODELS HAVE COME INTO BETTER AGREEMENT WITH THE TIMING OF THE FRONT BUT THE GFS TRACKS THE UPPER LEVEL DYNAMICS ACROSS SASKATCHEWAN WHILE THE ECMWF TAKES IT ACROSS MONTANA. WILL MENTION A SLIGHT CHANCE OF SNOW FOR NOW. COLD HIGH PRESSURE BUILDS INTO AREA WEDNESDAY NIGHT AND PREVAILS THROUGH FRIDAY WITH DRY WEATHER. NORTHWEST FLOW ALOFT WILL KEEP TEMPERATURES ON THE COLD SIDE OF NORMAL. UPPER RIDGE BUILDS INTO THE AREA BY NEXT WEEKEND WITH A WARMING TREND. FORRESTER && .AVIATION... VFR CONDITIONS ARE EXPECTED THROUGH THE AFTERNOON FOR ALL TERMINALS. IN THE WAKE OF THE COLD FRONT THAT WILL PASS THROUGH THIS EVENING WEST TO NORTHWEST WINDS WILL RAMP UP AFTER MIDNIGHT AND MAINTAIN SPEEDS OF 15 TO 25KTS FROM ABOUT 9Z SUNDAY TO 00Z MONDAY. CEILINGS... AND POSSIBLY VISIBILITY MAY DROP TO MVFR TONIGHT AS RAIN AND SNOW SHOWERS MOVE OVER THE TERMINALS. BRIEF PERIODS OF IFR CONDITIONS CAN NOT BE RULED OUT IF A MORE INTENSE BAND MOVES THROUGH THE AREA. SNOW WILL TAPER OFF SUNDAY MORNING AND AFTERNOON FOR ALL TERMINALS AS THE SYSTEM EXITS TO THE EAST. AEC && .GLASGOW WATCHES/WARNINGS/ADVISORIES... LAKE WIND ADVISORY FROM 1 AM TO 5 PM MST SUNDAY FOR FORT PECK LAKE FOR CENTRAL AND SOUTHEAST PHILLIPS...CENTRAL AND SOUTHERN VALLEY...GARFIELD...MCCONE...PETROLEUM. WINTER WEATHER ADVISORY UNTIL 11 AM MST SUNDAY FOR EASTERN ROOSEVELT...SHERIDAN. && $$ WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS BISMARCK ND
106 PM CST SAT NOV 16 2013 .UPDATE... ISSUED AT 107 PM CST SAT NOV 16 2013 LOW PRESSURE WILL REMAIN OVER THE AREA TODAY AS AN UPPER LEVEL TROUGH DIGS FROM THE NORTHERN ROCKIES INTO THE NORTHERN PLAINS. MAIN EARLY AFTERNOON UPDATES WERE TO LOWER TEMPERATURES AS EXTENSIVE CLOUD COVER AND LIGHT PRECIPITATION WILL LIMIT HEATING. ALSO ADJUSTED POPS BASED ON LATEST RADAR IMAGERY. UPDATE ISSUED AT 947 AM CST SAT NOV 16 2013 RADAR RETURNS CONTINUE OVER WESTERN AND NORTH CENTRAL NORTH DAKOTA AND HAVE EXPANDED AREAL COVERAGE OF SLIGHT CHANCE POPS. ALSO ADDED A SLIGHT CHANCE OF PRECIPITATION OVER THE FAR SOUTHEAST COUNTIES AS RETURNS HAVE INCREASED HERE AS WELL OVER THE PAST FEW HOURS. PRECIPITATION WILL BE RAIN IN THE SOUTHEAST WITH A RAIN SNOW MIX NORTH AND WEST FOR ANOTHER HOUR OR TWO...BEFORE RAIN THIS AFTERNOON. PRECIPITATION AMOUNTS TODAY WILL BE LIGHT. A FEW AREAS OF SUN OVER THE FAR SOUTH CENTRAL YET THIS MORNING...BUT CLOUDS WILL CONTINUE TO INCREASE DURING THE DAY. WILL TAKE A CLOSER LOOK AT TEMPERATURES LATE MORNING/EARLY THIS AFTERNOON. UPDATE ISSUED AT 629 AM CST SAT NOV 16 2013 EARLY MORNING RADAR MOSAIC SHOWS A FEW RETURNS ACROSS THE NORTHWEST AND SOUTHEAST PARTS OF THE STATE. THE 12Z KBIS SOUNDING SHOWS THERE IS QUITE A BIT OF DRY LOW LEVEL AIR TO OVERCOME...SO MAINLY VIRGA IS EXPECTED OVER THE NEXT FEW HOURS. THE EXCEPTION WOULD BE IN THE NORTHWEST WHERE THE LATEST RAP SUGGESTS THERE COULD BE LIGHT PRECIPITATION THIS MORNING. ESTEVAN HAS REPORTED A FEW FLURRIES IN THE PAST HOUR...SO WILL INCREASE THE COVERAGE OF THE SLIGHT CHANCES POPS THIS MORNING TO FALL IN LINE CLOSER TO THE COVERAGE SHOWN BY THE RAP. DO NOT EXPECT MUCH ACCUMULATION...THUS KEPT POPS LOW. UPDATED TEMPERATURES TO BETTER REFLECT CURRENT CONDITIONS...OTHERWISE THE FORECAST LOOKS TO BE IN GOOD SHAPE. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 310 AM CST SAT NOV 16 2013 A WINTER WEATHER ADVISORY WILL NOT BE ISSUED FOR THIS EVENT...AT LEAST NOT WITH THIS FORECAST CYCLE...BASED ON CURRENT EXPECTATIONS OF JUST AN INCH OR TWO TOTAL SNOWFALL SATURDAY NIGHT THROUGH SUNDAY. WE ARE DEEP ENOUGH NOW INTO THE SNOW SEASON WHERE AN ADVISORY IS NOT JUSTIFIED. WE MAY OPT TO HIGHLIGHT THE EVENT THROUGH A SPECIAL WEATHER STATEMENT AS SUNDAY WILL BE WINDY AND MUCH COLDER. TWO POINTS OF INTEREST FOR THE SHORT TERM. THE FIRST IS THE ABOVE NORMAL TEMPERATURES FOR TODAY...SATURDAY. ENJOY IT IF YOU CAN AS HIGH TEMPERATURES WILL BE 5 TO 10 DEGREES ABOVE MID NOVEMBER NORMALS. COOLER THAN FRIDAY...BUT STILL ABOVE NORMAL. THE SECOND POINT IS THE COLDER WEATHER MOVING IN FOR TONIGHT WITH RAIN CHANGING TO SNOW. FOR TODAY...SURFACE HIGH PRESSURE AND MID LEVEL RIDGING WILL SLIDE / SHIFT OFF TO THE EAST AS AN OPEN MID LEVEL WAVE APPROACHES FROM THE NORTHWEST. AHEAD OF THE SURFACE LOW...CLOUDS WERE ALREADY ADVANCING INTO THE WESTERN PART OF THE FORECAST AREA...AND WILL MAKE FOR A MOSTLY CLOUDY AFTERNOON ACROSS ALL OF THE FORECAST AREA. A WEAK WARM FRONT SLIDING THROUGH LATER TODAY WILL PUSH TEMPERATURES INTO THE 40S FOR HIGHS...AND BRING THE CHANCE FOR AN ISOLATED RAIN SHOWER TO THE WEST. FOR TONIGHT...LARGE SCALE LIFTING INCREASES AS THE MID LEVEL AND SURFACE WAVE APPROACH. COOLING WILL BE DELAYED...AS WE WILL BE ON THE SO CALLED WARM SIDE OF STORM...UNTIL AFTER 9 PM OR SO. PRECIPITATION STARTS AS RAIN AND THEN TRANSITIONS TO SNOW AS THE ATMOSPHERE COOLS. THE CHANGE TO SNOW OCCURS ALONG HIGHWAY 2 AROUND 9 PM CST...AND ALONG I-94 AROUND 11 PM OR MIDNIGHT CST. THE SNOW THROUGH DAYBREAK SUNDAY WILL BE LIGHT IN INTENSITY. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 310 AM CST SAT NOV 16 2013 SUNDAY WILL BEGIN WITH A LARGE TROUGH ACROSS THE CENTRAL UNITED STATES WHICH HELPS PUSH ANOTHER COLD FRONT THROUGH THE NORTHERN PLAINS. SHORT TERM MODELS HAVE COME INTO BETTER AGREEMENT REGARDING PRECIPITATION CHANCES...AND SUGGEST HIGHER CHANCES FOR SUNDAY MORNING. HAVE INCREASED POPS ACCORDINGLY AND NOW HAVE POPS APPROACHING CATEGORICAL IN THE NORTHWEST. IT APPEARS THE MAJORITY OF THE PRECIPITATION WILL FALL AS SNOW AS COLDER AIR WORKS IT WAY INTO THE REGION. SNOW AMOUNTS SUNDAY SHOULD GENERALLY STAY LESS THAN 1.5 INCHES. HIGH TEMPERATURES IN THE MID 20S TO MID 30S ON SUNDAY WILL BE MUCH COOLER THAN THOSE EXPECTED FOR TODAY (SATURDAY). THE COLDER TEMPERATURES COMBINED WITH A GUSTY NORTHWESTERLY WIND WILL MAKE FOR A RATHER BLUSTERY DAY. SURFACE HIGH PRESSURE BUILDS IN SUNDAY NIGHT...AND WILL GO DRY ACROSS THE FORECAST AREA. THAT BEING SAID...SOME MODEL SOLUTIONS DO SUGGEST THE POSSIBILITY OF LINGERING LIGHT SNOW IN THE FAR EAST EARLY SUNDAY EVENING...BUT DID NOT FEEL CONFIDENT ENOUGH TO ADD A POP AT THE MOMENT. H5 HEIGHTS RISE MONDAY WITH WARMER AIR RETURNING TO THE NORTHERN PLAINS FOR EARLY NEXT WEEK. THE WARMER AIR DOES NOT STAY IN PLACE FOR VERY LONG WITH ANOTHER COLD FRONT DROPPING ACROSS DAKOTAS WEDNESDAY INTO WEDNESDAY NIGHT. THE FRONT WILL ALSO BRING ANOTHER CHANCE OF PRECIPITATION...AGAIN MAINLY IN THE FORM OF SNOW. AT THE MOMENT...IT DOES NOT APPEAR TO BE A SIGNIFICANT PRECIPITATION MAKER. DRIER WEATHER TAKES HOLD AGAIN FOR THURSDAY AND FRIDAY. WARMER AIR RETURNS AGAIN FRIDAY INTO NEXT WEEKEND. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 107 PM CST SAT NOV 16 2013 THIS AFTERNOON RAIN WILL IMPACT KISN AND KMOT...MOVING INTO KDIK...KBIS...AND KJMS THROUGH THE EVENING. RAIN IS EXPECTED TO TURN TO SNOW INTO THE OVERNIGHT HOURS. THERE IS SOME UNCERTAINTY AS TO WHEN THE CHANGEOVER WILL OCCUR. DURING THE TAF PERIOD...EXPECT MVFR CONDITIONS WITH LOWER CEILINGS AND REDUCED VISIBILITIES. WINDS WILL GRADUALLY INCREASE THROUGH THE END OF THE PERIOD. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...TWH SHORT TERM...JPM LONG TERM...CK AVIATION...AC
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1157 AM CST SAT NOV 16 2013 .UPDATE... 18Z AVIATION DISCUSSION UPDATED BELOW. FOG IS STILL PRESENT ACROSS PARTS OF NORTHEAST SOUTH DAKOTA AND WEST CENTRAL MINNESOTA. THE KATY OB HAS IMPROVED FROM A QUARTER MILE VISIBILITY UP TO A HALF...BUT WITHOUT ANYTHING TO SCOUR OUT THE LOW LEVEL MOISTURE...LEFT THE FOG MENTION IN THROUGH THE EARLY AFTERNOON HOURS. A NARROW AREA OF SPRINKLES HAS DEVELOPED ALONG A LINE FROM EUREKA TO BOWDLE TO HOVEN...SO ADDED THIS MENTION INTO THE FORECAST...AND ADJUSTED THE TIMING OF POPS MOVING INTO NORTHEAST SOUTH DAKOTA TO MATCH CURRENT RADAR TRENDS. OTHERWISE...THE OVERALL FORECAST REMAINS ON TRACK THIS MORNING. && .PREVIOUS DISCUSSION... .SHORT TERM...TODAY THROUGH MONDAY WEAK UPPER LEVEL DISTURBANCE DRIFTING NORTHEAST ACROSS THE AREA EARLY THIS MORNING. WEAK LIFT SLIDING THROUGH AND FOG SATELLITE SHOWING SOME TEXTURE TO THE MID LEVEL DECK MOVING NORTHEAST THROUGH THE CWA. RADAR HAS SOME VERY LIGHT RETURNS WITHIN THE MID LEVEL DECK......MAYBE JUST A COUPLE SPRINKLES. MAIN THING TO WATCH TODAY IS THE SECONDARY WAVE WHICH IS A TAD FURTHER SOUTH...AND ITS EXPECTED DEVELOPMENT OF SHOWERS ACROSS SOUTHEAST SOUTH DAKOTA INTO MINNESOTA. EVEN THIS CLOSE TO EVENT TIME...MODELS STILL HAVING A TOUGH TIME DETERMINING PLACEMENT OF PRECIP AND THE HANDLING OF THE STRATUS DECK WELL TO THE SOUTH. NO SIGN OF STRATUS ANYWHERE NEAR THE CWA...WITH THINGS RIGHT NOW PUSHED WELL SOUTH INTO KANSAS AND MISSOURI. ALTHOUGH...MODELS STILL SUGGESTING SOME DEVELOPMENT SHORTLY AFTER 12Z. VERY LOW CONFIDENCE IN JUST HOW FAST STRATUS MAKES IT INTO SOUTHEAST SOUTH DAKOTA AND THE SOUTHEAST CWA. FOR RIGHT NOW HAVE CONSTRUCTED SKY GRIDS TO SHOW SOME INCREASE IN CLOUDS LATER THIS MORNING. FEEL THERE WILL BE AT LEAST SOME DEVELOPMENT OF STRATUS BY LATER TODAY. REMOVED DRIZZLE FROM THE FORECAST AS SOUNDINGS OVER THE SOUTHEAST CWA JUST DO NOT SUPPORT IT. NO DEEP MOISTURE LAYER DOWN LOW AT ALL. BETTER SIGNAL SHOWS UP CLOSE TO SIOUX FALLS AREA. WILL LEAVE IN 20 POPS ACROSS THE FAR EASTERN CWA TO SORT OF GO ALONG WITH WHAT THE HRRR AND ABR 4KM MODELS ARE SHOWING. AT THIS POINT...NOT REALLY BUYING INTO THE MORE QPF-HAPPY EC AND GFS WHICH HAS PRECIP BACK FURTHER WEST INTO THE JAMES VALLEY WITHIN A STRATUS DECK. ATTENTION THEN TURNS TO THE STRONGER UPPER LEVEL SHORTWAVE ENERGY MOVING ACROSS THE DAKOTAS LATE TONIGHT THROUGH SUNDAY. MODELS CONTINUE TO WARM THE LOWER LEVELS OF THE ATMOSPHERE AND HAVE INCREASED HIGHS ON SUNDAY. NOW IT APPEARS MOST OF TONIGHT WILL BE DRY WITH CHANCES MOVING INTO THE WESTERN CWA BY 12Z SUNDAY. LEFT PRECIP MOSTLY RAIN THOUGH AS THERMAL PROFILES STILL FAIRLY MILD THROUGH THE NIGHT. AROUND 12Z SUNDAY AND SHORTLY AFTER THE COLUMN BEGINS TO COOL ENOUGH TO SUPPORT MAINLY SNOWFALL DURING THE MORNING HOURS...BUT WARMING AGAIN DURING THE AFTERNOON. MODELS HAVING A TOUGH TIME WITH THIS SHORTWAVE ENERGY AS WELL IN REGARDS TO PRECIP PLACEMENT. OVERALL...A FAIRLY LOW CONFIDENCE FORECAST UNFORTUNATELY. BUT HAVING SAID THAT...IT DOES APPEAR THE BEST CHANCE FOR PRECIP IN THE SHORT TERM WILL BE WITH WHATEVER MATERIALIZES WITHIN THE UPPER LEVEL SHORTWAVE ENERGY LATER TONIGHT THROUGH SUNDAY. ALSO NEED TO MENTION THE WINDS ON SUNDAY AS THEY WILL GET RATHER GUSTY WITHIN A TIGHTENING PRESSURE GRADIENT. COULD BE LOOKING AT WIND ADVISORY SPEEDS OVER THE WESTERN CWA ON SUNDAY. WILL CONTINUE TO MONITOR. .LONG TERM...MONDAY NIGHT THROUGH FRIDAY SEEMS THE GLOBAL SPECTRAL MODELS ARE CONTINUING TO HAVE A TOUGH TIME RESOLVING FLOW PATTERN EVOLUTION AND SHORT-WAVE TIMING IN THE FARTHER OUT FORECAST TIME PERIODS. FOR THE PAST COUPLE OF MORNINGS THE GFS AND ECMWF HAVE BEEN HINTING AT THE DEVELOPMENT OF A PERIOD OF SPLIT FLOW IN THE OUT PERIODS. MODELS ARE KNOWN TO HAVE DIFFICULTIES RESOLVING FLOW PATTERN FEATURES IN THE SHORTER RANGE FORECAST PERIODS /CONSIDERABLY LOWER FORECAST CONFIDENCE/ WHEN A SPLIT FLOW PATTERN IS OCCURRING OR IMMINENT...LET ALONE THE LONGER RANGE FORECAST TIME-FRAME. SO IT WOULD BE SAFE TO SAY...FORECASTER CONFIDENCE IN LONGER RANGE SOLUTIONS IS LOWER THAN NORMAL. THE ECMWF STILL HAS A STRONG COLD FRONT WORKING THROUGH THE REGION BY THE MIDDLE OF NEXT WEEK. IT DOES NOT HAVE A BAND OF SNOW WORKING ACROSS THE CWA...THOUGH...FOR WEDNESDAY NIGHT. THAT FEATURE HAS SLOWED BY ABOUT 12 HOURS AND IS FURTHER SOUTH NOW ACROSS NEBRASKA. THE GFS COLD FRONTAL FEATURE STILL SEEMS TO LAG BEHIND THE ECMWF BY ABOUT 12 HOURS...WHILE THE GEM REMAINS APPX 12 HOURS FASTER THAN THE ECMWF. SO...WITH FRONTAL TIMING DIFFERENCES STILL ABOUNDING...AND PRECIPITATION TIMING/PLACEMENT FORECASTS STILL EVOLVING...SEEMS LIKE GOING AS DRY AS POSSIBLE FOR AS MUCH OF THE LONG TERM AS POSSIBLE IS A GOOD MOVE THIS MORNING. AT THIS POINT...THURSDAY STILL LOOKS LIKE THE COLDEST DAY OF THE EXTENDED...ALTHOUGH THAT WILL PROBABLY CHANGE BY TOMORROW MORNING...AS WELL. && .AVIATION... 18Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS ONE UPPER LEVEL LOW PRESSURE SYSTEM WAS LEAVING THE EASTERN PART OF THE REGION THIS AFTERNOON WHILE ANOTHER STRONGER SYSTEM WAS MOVING IN FROM THE NORTHWEST. THE LOW STRATUS AND FOG AT ATY IS EXPECTED TO BREAK UP/LIFT THROUGH THE AFTERNOON...POSSIBLY REFORMING AGAIN TONIGHT. AT THIS TIME...LEFT IT OUT OF ATY FOR TONIGHT AND WILL HAVE TO WATCH. OTHERWISE...AS THE MID AND HIGH LEVEL CLOUDS EXIT WITH THE FIRST SYSTEM MORE VFR CLOUDS WILL SPREAD IN WITH THE NEXT SYSTEM. SOME SCATTERED LIGHT RAIN SHOWERS WILL ALSO SPREAD IN FOR LATER TONIGHT AND SUNDAY MORNING POSSIBLY AFFECTING THE TERMINALS WITH NO REDUCTION IN VISIBILITY EXPECTED. MAY HAVE TO INSERT IN TERMINALS AS WE GET CLOSER. NORTHWEST WINDS ARE EXPECTED TO ALSO PICK UP ON SUNDAY MORNING. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. && $$ UPDATE...SERR SHORT TERM...TMT LONG TERM...DORN AVIATION...MOHR WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1041 AM CST SAT NOV 16 2013 .UPDATE... FOG IS STILL PRESENT ACROSS PARTS OF NORTHEAST SOUTH DAKOTA AND WEST CENTRAL MINNESOTA. THE KATY OB HAS IMPROVED FROM A QUARTER MILE VISIBILITY UP TO A HALF...BUT WITHOUT ANYTHING TO SCOUR OUT THE LOW LEVEL MOISTURE...LEFT THE FOG MENTION IN THROUGH THE EARLY AFTERNOON HOURS. A NARROW AREA OF SPRINKLES HAS DEVELOPED ALONG A LINE FROM EUREKA TO BOWDLE TO HOVEN...SO ADDED THIS MENTION INTO THE FORECAST...AND ADJUSTED THE TIMING OF POPS MOVING INTO NORTHEAST SOUTH DAKOTA TO MATCH CURRENT RADAR TRENDS. OTHERWISE...THE OVERALL FORECAST REMAINS ON TRACK THIS MORNING. && .PREVIOUS DISCUSSION... .SHORT TERM...TODAY THROUGH MONDAY WEAK UPPER LEVEL DISTURBANCE DRIFTING NORTHEAST ACROSS THE AREA EARLY THIS MORNING. WEAK LIFT SLIDING THROUGH AND FOG SATELLITE SHOWING SOME TEXTURE TO THE MID LEVEL DECK MOVING NORTHEAST THROUGH THE CWA. RADAR HAS SOME VERY LIGHT RETURNS WITHIN THE MID LEVEL DECK......MAYBE JUST A COUPLE SPRINKLES. MAIN THING TO WATCH TODAY IS THE SECONDARY WAVE WHICH IS A TAD FURTHER SOUTH...AND ITS EXPECTED DEVELOPMENT OF SHOWERS ACROSS SOUTHEAST SOUTH DAKOTA INTO MINNESOTA. EVEN THIS CLOSE TO EVENT TIME...MODELS STILL HAVING A TOUGH TIME DETERMINING PLACEMENT OF PRECIP AND THE HANDLING OF THE STRATUS DECK WELL TO THE SOUTH. NO SIGN OF STRATUS ANYWHERE NEAR THE CWA...WITH THINGS RIGHT NOW PUSHED WELL SOUTH INTO KANSAS AND MISSOURI. ALTHOUGH...MODELS STILL SUGGESTING SOME DEVELOPMENT SHORTLY AFTER 12Z. VERY LOW CONFIDENCE IN JUST HOW FAST STRATUS MAKES IT INTO SOUTHEAST SOUTH DAKOTA AND THE SOUTHEAST CWA. FOR RIGHT NOW HAVE CONSTRUCTED SKY GRIDS TO SHOW SOME INCREASE IN CLOUDS LATER THIS MORNING. FEEL THERE WILL BE AT LEAST SOME DEVELOPMENT OF STRATUS BY LATER TODAY. REMOVED DRIZZLE FROM THE FORECAST AS SOUNDINGS OVER THE SOUTHEAST CWA JUST DO NOT SUPPORT IT. NO DEEP MOISTURE LAYER DOWN LOW AT ALL. BETTER SIGNAL SHOWS UP CLOSE TO SIOUX FALLS AREA. WILL LEAVE IN 20 POPS ACROSS THE FAR EASTERN CWA TO SORT OF GO ALONG WITH WHAT THE HRRR AND ABR 4KM MODELS ARE SHOWING. AT THIS POINT...NOT REALLY BUYING INTO THE MORE QPF-HAPPY EC AND GFS WHICH HAS PRECIP BACK FURTHER WEST INTO THE JAMES VALLEY WITHIN A STRATUS DECK. ATTENTION THEN TURNS TO THE STRONGER UPPER LEVEL SHORTWAVE ENERGY MOVING ACROSS THE DAKOTAS LATE TONIGHT THROUGH SUNDAY. MODELS CONTINUE TO WARM THE LOWER LEVELS OF THE ATMOSPHERE AND HAVE INCREASED HIGHS ON SUNDAY. NOW IT APPEARS MOST OF TONIGHT WILL BE DRY WITH CHANCES MOVING INTO THE WESTERN CWA BY 12Z SUNDAY. LEFT PRECIP MOSTLY RAIN THOUGH AS THERMAL PROFILES STILL FAIRLY MILD THROUGH THE NIGHT. AROUND 12Z SUNDAY AND SHORTLY AFTER THE COLUMN BEGINS TO COOL ENOUGH TO SUPPORT MAINLY SNOWFALL DURING THE MORNING HOURS...BUT WARMING AGAIN DURING THE AFTERNOON. MODELS HAVING A TOUGH TIME WITH THIS SHORTWAVE ENERGY AS WELL IN REGARDS TO PRECIP PLACEMENT. OVERALL...A FAIRLY LOW CONFIDENCE FORECAST UNFORTUNATELY. BUT HAVING SAID THAT...IT DOES APPEAR THE BEST CHANCE FOR PRECIP IN THE SHORT TERM WILL BE WITH WHATEVER MATERIALIZES WITHIN THE UPPER LEVEL SHORTWAVE ENERGY LATER TONIGHT THROUGH SUNDAY. ALSO NEED TO MENTION THE WINDS ON SUNDAY AS THEY WILL GET RATHER GUSTY WITHIN A TIGHTENING PRESSURE GRADIENT. COULD BE LOOKING AT WIND ADVISORY SPEEDS OVER THE WESTERN CWA ON SUNDAY. WILL CONTINUE TO MONITOR. .LONG TERM...MONDAY NIGHT THROUGH FRIDAY SEEMS THE GLOBAL SPECTRAL MODELS ARE CONTINUING TO HAVE A TOUGH TIME RESOLVING FLOW PATTERN EVOLUTION AND SHORT-WAVE TIMING IN THE FARTHER OUT FORECAST TIME PERIODS. FOR THE PAST COUPLE OF MORNINGS THE GFS AND ECMWF HAVE BEEN HINTING AT THE DEVELOPMENT OF A PERIOD OF SPLIT FLOW IN THE OUT PERIODS. MODELS ARE KNOWN TO HAVE DIFFICULTIES RESOLVING FLOW PATTERN FEATURES IN THE SHORTER RANGE FORECAST PERIODS /CONSIDERABLY LOWER FORECAST CONFIDENCE/ WHEN A SPLIT FLOW PATTERN IS OCCURRING OR IMMINENT...LET ALONE THE LONGER RANGE FORECAST TIME-FRAME. SO IT WOULD BE SAFE TO SAY...FORECASTER CONFIDENCE IN LONGER RANGE SOLUTIONS IS LOWER THAN NORMAL. THE ECMWF STILL HAS A STRONG COLD FRONT WORKING THROUGH THE REGION BY THE MIDDLE OF NEXT WEEK. IT DOES NOT HAVE A BAND OF SNOW WORKING ACROSS THE CWA...THOUGH...FOR WEDNESDAY NIGHT. THAT FEATURE HAS SLOWED BY ABOUT 12 HOURS AND IS FURTHER SOUTH NOW ACROSS NEBRASKA. THE GFS COLD FRONTAL FEATURE STILL SEEMS TO LAG BEHIND THE ECMWF BY ABOUT 12 HOURS...WHILE THE GEM REMAINS APPX 12 HOURS FASTER THAN THE ECMWF. SO...WITH FRONTAL TIMING DIFFERENCES STILL ABOUNDING...AND PRECIPITATION TIMING/PLACEMENT FORECASTS STILL EVOLVING...SEEMS LIKE GOING AS DRY AS POSSIBLE FOR AS MUCH OF THE LONG TERM AS POSSIBLE IS A GOOD MOVE THIS MORNING. AT THIS POINT...THURSDAY STILL LOOKS LIKE THE COLDEST DAY OF THE EXTENDED...ALTHOUGH THAT WILL PROBABLY CHANGE BY TOMORROW MORNING...AS WELL. && .AVIATION... 12Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS VFR SHOULD PREVAIL TODAY AND TONIGHT AT KMBG...KPIR AND KABR. THERE MAY BE A COUPLE SPRINKLES OR FLURRIES AT KPIR AND KABR AND ALONG A LINE BETWEEN THESE TWO TERMINALS THROUGH ABOUT MID-DAY TODAY. BUT...THIS SHOULD NOT IMPACT CIGS OR VISBIES. KATY CONTINUES TO REMAIN THE CONCERN FOR SUB-VFR CONDITIONS. SURFACE TO TOP-OF-THE-BOUNDARY-LAYER MOISTURE CONTINUES TO INCREASE THIS MORNING ON LIGHT SOUTH WINDS. UPSTREAM FROM KATY...SITES ACROSS SERN SOUTH DAKOTA AND SWRN MINNESOTA ARE REPORTING IFR CIGS AND IN SOME CASES MVFR/IFR VISBIES. SEEMS INCREASINGLY PROBABLE THAT KATY WILL BE DOWN INTO SOME FORM OF SUB-VFR FLYING CONDITIONS WITHIN THE NEXT 3 TO 6 HOURS. THERE IS ALSO A CHANCE FOR SOME RAIN AT KATY MAINLY LATER THIS AFTERNOON FOR A FEW HOURS AS A LOW PRESSURE SYSTEM LIFTS NEWD ACROSS THE REGION. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. && $$ UPDATE...SERR SHORT TERM...TMT LONG TERM...DORN AVIATION...DORN WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS SPOKANE WA
1015 AM PST Sat Nov 16 2013 .SYNOPSIS... Low pressure will continue to bring rain and snow snow showers across Inland Northwest today. Accumulating snow are expected in the mountains, as well as some northern valley location. A shower threat will linger into Sunday and early Monday. A much wetter, but warmer system moves into the area late Monday. It impacts will continue Tuesday and Wednesday. && .DISCUSSION... Morning update: low pressure/inverted surface trough will continue to migrate across the region this morning and afternoon, weakening as it does. This will keep scattered to locally numerous rain and snow showers alive across the eastern third of WA/north ID. The west to northwest flow will continue to focus some of the higher snow amounts toward the ID mountains through tonight. Some brief moderate to heavy snow showers will also be possible in some of the heavier bands around the northeast WA mtns, the Blues and Camas Prairie through this afternoon. Thus winter storm warnings will continue through tonight over ID, while advisories will linger over the northeast WA mtns, Blues and Camas Prairie through afternoon...largely above about 2000 to 3500 feet. I removed the advisory from the Okanogan Highlands, where shower coverage is winding down to mainly isolated. I also let the advisory around the COE zone expire; though some snow showers will continue through the afternoon they will be mixed with rain as temperatures are warming above freezing and this should limit the amount of accumulation. I did continue the winter weather advisory for the Cascade crest. A look at webcams, especially around Stevens Pass, indicates some unpleasant conditions. The HRRR also indicates some moderate bands of snow continue in this region through at least this afternoon. We will have to watch trends to see if this needs to be extended longer. /J. Cote` && .AVIATION... 18Z TAFS: low pressure over eastern WA/north ID will continue to focus MVFR/lcl IFR cigs and vis with scattered rain and snow showers around KGEG-KCOE and KPUW, especially before evening. A period of VFR conditions is possible this afternoon, with breezy conditions, before cigs drop toward MVFR/lcl IFR after 03-08Z tonight through Sunday. A threat of showers will be also found near KLWS through early evening. Toward Sunday morning a small shower near KEAT as the next system approaches. /J. Cote` && .PRELIMINARY POINT TEMPS/POPS... Spokane 38 27 41 31 42 35 / 20 10 40 40 30 60 Coeur d`Alene 38 26 39 29 41 34 / 40 20 50 50 30 60 Pullman 38 29 41 32 44 34 / 50 10 30 30 10 40 Lewiston 41 34 46 34 47 37 / 40 20 30 20 10 40 Colville 40 21 39 27 42 32 / 20 20 50 50 40 70 Sandpoint 38 25 38 30 40 33 / 60 40 60 70 50 60 Kellogg 34 28 36 27 39 34 / 70 70 50 60 20 50 Moses Lake 47 29 49 32 47 34 / 10 0 10 10 20 60 Wenatchee 45 32 45 33 46 35 / 10 0 10 10 20 60 Omak 42 27 41 30 43 33 / 10 0 30 20 30 70 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...Winter Storm Warning until 4 AM PST Sunday for Central Panhandle Mountains-Northern Panhandle. Winter Weather Advisory until 4 PM PST this afternoon for Lewis and Southern Nez Perce Counties. WA...Winter Weather Advisory until 4 PM PST this afternoon for East Slopes Northern Cascades-Northeast Blue Mountains. Winter Weather Advisory until 4 PM PST this afternoon for Northeast Mountains. && $$